I'm trying to modify the filter ui with a custom function that i passed to the kendo UI fuction.

here's my code :

@using Alstom_penali.Models.database;
@{
    ViewBag.Title = "Tutte le penali";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<div class="container-fluid">
    <div class="row">

        <h3>@ViewBag.Title</h3>

        @*sotto permessi*@
        @if (ViewBag.CanUploadFilePenali == string.Empty)
        {
            @(Html.Kendo().Upload()
                .Name("up_supplychain")
                .Messages(y => y.Select("Upload excel penali").UploadSelectedFiles("Avvia"))
                .HtmlAttributes(new { accept = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet,application/vnd.ms-excel" })
                .Multiple(false)
                .ShowFileList(false)
                .Events(e => e.Success("onUploadSuccess"))
                .Async(a => a
                    .Save("SuppChainExcelRead", "Summary", new { operation = "save" })
                    .Remove("SuppChainExcelRead", "Summary", new { operation = "remove" })
                    .AutoUpload(false)
                )
            )
            <br />
        }




        @if (ViewBag.CanViewSummaryAll == string.Empty)
        {
            @(Html.Kendo().Grid<PenaliModel>
                ()
                .Name("grid")
                .Events(e => e.ExcelExport("excelExport"))
                .Columns(
                columns =>
                {

                    columns.Bound(c => c.PO_Number).Title("PO Number").Width(125).Locked(true);
                    columns.Bound(c => c.Pos).Width(100).Locked(true);
                    columns.Bound(c => c.ddl_stato).Title("STATO").Width(180).Filterable(false).Sortable(false).Locked(true).ClientTemplate("#=ddl_stato.Text#").EditorTemplateName("DropDownEditor");
                    columns.Bound(c => c.ddl_Responsabilita).Title("Responsabilità").Width(200).Filterable(false).Sortable(false).Locked(false).ClientTemplate("#=descriptionTemplate(data) #").EditorTemplateName("DropDownEditorResponsabilita");
                    columns.Bound(c => c.isConQ).Title("Tipo").Width(125)
                        .Filterable(filter=> filter.UI("isConQRadioFilter"))
                        .Sortable(false)
                        .Locked(false)
                        .ClientTemplate("#=typeTemplate(data) #");

                    columns.Command(command => { command.Edit().Text("Modifica"); }).Width(100);

                    columns.Bound(c => c.Progressivo_Conferma).Width(150).Title("CONQ Report");
                    columns.Bound(c => c.DataInvioConferma).Title("Data Invio CONQ").Width(200).Format("{0:dd/MM/yyyy HH:mm}");

                    columns.Bound(c => c.NCR).Width(100);
                    columns.Bound(c => c.SupplierName).Title("Supplier Name").Width(200).Format("{0:n2}");
                    columns.Bound(c => c.ProgettoSito).Title("MBTO").Width(150);
                    columns.Bound(c => c.ImportoDaAddebitare).Title("Importo").Width(100).Format("{0:n2}");
                    columns.Bound(c => c.Importo_Negoziato).Title("Importo Negoziato").Width(150).Format("{0:n2}");
                    columns.Bound(c => c.Quality_Owner).Title("Quality Owner").Width(200);
                    columns.Bound(c => c.Progressivo_Avviso).Width(150).Title("ID_CLAIM");

                    columns.Bound(c => c.DataInvioAvviso).Title("Data Invio CLAIM ").Width(150).Format("{0:dd/MM/yyyy HH:mm}");
                    columns.Bound(c => c.DataInvioPenale).Title("Data Invio penale").Width(150).Format("{0:dd/MM/yyyy HH:mm}");
                    columns.Bound(c => c.NotaDebitoNr).Title("Nota debito").Width(125);
                    columns.Bound(c => c.DataInvioStorno).Title("Data Invio storno").Width(150).Format("{0:dd/MM/yyyy HH:mm}");
                    columns.Bound(c => c.NotaCreditoNr).Title("Nota credito").Width(125);

                    columns.Bound(c => c.Id);

                    columns.Bound(c => c.WBS).Width(200);
                    columns.Bound(c => c.Progressivo).Width(150);
                    columns.Bound(c => c.YearMonth).Width(150);

                    columns.Bound(c => c.Material).Width(200);
                    columns.Bound(c => c.Description).Width(300).ClientTemplate("<span class='ellipsis'>#:Description#</span>");
                    columns.Bound(c => c.Del_Note_Nr).Width(150);
                    columns.Bound(c => c.EmailProcurement).Title("Material planner").Width(200);

                    columns.Bound(c => c.TotalOrderQty).Width(150);
                    columns.Bound(c => c.ReceivedQtyInDelay).Width(150);
                    columns.Bound(c => c.OrderValue).Width(150).Format("{0:n2}");
                    columns.Bound(c => c.Stat_Del_Date).Width(150).Format("{0:dd/MM/yyyy HH:mm}");
                    columns.Bound(c => c.Del_Date).Width(150).Format("{0:dd/MM/yyyy HH:mm}");
                    columns.Bound(c => c.WeeksOfDelay).Width(150);
                    columns.Bound(c => c.ReceivedValue).Width(150);
                    columns.Bound(c => c.DataCreazione).Width(150).Format("{0:dd/MM/yyyy HH:mm}");
                    columns.Bound(c => c.DataModifica).Width(150).Format("{0:dd/MM/yyyy HH:mm}");


                    columns.Command(command => { command.Destroy().Text("Elimina"); }).Width(100);

                })
                .HtmlAttributes(new { style = "height: 500px;" })
                .ToolBar(tools => tools.Excel().Text("Esporta excel"))
                .Excel(excel => excel.AllPages(true).FileName("Penali.xlsx"))
                .Editable(editable =>
                {
                    editable.Mode(GridEditMode.InLine);
                    editable.ConfirmDelete("Sei sicuro?");
                })
                .Scrollable()
                .Groupable()
                .Filterable(filterable => filterable
                    .Operators(operators => operators
                    .ForString(str => str.Clear()
                    .IsEqualTo("E' uguale a").StartsWith("Inizia con").EndsWith("Finisce con")
                    .Contains("Contiene").DoesNotContain("Non contiene"))
                    .ForDate(dt => dt.Clear()
                    .IsGreaterThanOrEqualTo("Dopo o uguale al").IsLessThanOrEqualTo("Prima o uguale del"))

                ))
                .Sortable()
                .Selectable()
                .Pageable(pageable => pageable
                .Refresh(true)
                .PageSizes(true)
                )
                .DataSource(dataSource => dataSource
                .Ajax()
                .Model(model =>
                {

                    model.Id(p => p.Id);
                    model.Field(p => p.DataInvioAvviso).Editable(false);
                    model.Field(p => p.DataInvioPenale).Editable(false);
                    model.Field(p => p.DataInvioStorno).Editable(false);
                    model.Field(p => p.DataCreazione).Editable(false);
                    model.Field(p => p.DataModifica).Editable(false);
                    model.Field(p => p.Del_Date).Editable(false);
                    model.Field(p => p.Del_Note_Nr).Editable(false);
                    model.Field(p => p.Description).Editable(false);
                    model.Field(p => p.Det_Selected).Editable(false);
                    model.Field(p => p.EmailProcurement).Editable(false);
                    model.Field(p => p.ImportoDaAddebitare).Editable(false);
                    model.Field(p => p.Importo_Negoziato).Editable(false);
                    model.Field(p => p.Material).Editable(false);
                    model.Field(p => p.NotaCreditoNr).Editable(false);
                    model.Field(p => p.NotaDebitoNr).Editable(false);
                    model.Field(p => p.OrderValue).Editable(false);
                    model.Field(p => p.PO_Number).Editable(false);
                    model.Field(p => p.Pos).Editable(false);
                    model.Field(p => p.ProgettoSito).Editable(false);
                    model.Field(p => p.Progressivo).Editable(false);
                    model.Field(p => p.ReceivedQtyInDelay).Editable(false);
                    model.Field(p => p.ReceivedValue).Editable(false);
                    model.Field(p => p.Stat_Del_Date).Editable(false);
                    model.Field(p => p.SupplierName).Editable(false);
                    model.Field(p => p.TotalOrderQty).Editable(false);
                    model.Field(p => p.WBS).Editable(false);
                    model.Field(p => p.WeeksOfDelay).Editable(false);
                    model.Field(p => p.YearMonth).Editable(false);
                    model.Field(p => p.NCR).Editable(false);
                    model.Field(p => p.Progressivo_Avviso).Editable(false);
                    model.Field(p => p.Progressivo_Conferma).Editable(false);
                    model.Field(p => p.Quality_Owner).Editable(false);

                    model.Field(p => p.ddl_stato).DefaultValue(new SelectListItem() { }); //unico editabile
                    model.Field(p => p.ddl_Responsabilita).DefaultValue(new SelectListItem() { });
                    model.Field(p => p.isConQ).Editable(false);
                    model.Field(p => p.DataInvioConferma).Editable(false);
                })
                .Events(events =>
                {

                    events.RequestEnd("onRequestEnd");
                    events.Error("onGridError");

                })
                .Read(read => read.Action("Penali_List", "Summary"))
                .Update(update => update.Action("Penali_Update", "Summary"))
                .Destroy(update => update.Action("Penali_Destroy", "Summary"))

                .PageSize(10)
                )
    )
        }
        else
        {
            <p style="font-size:16px;color:red">@ViewBag.CanViewSummaryAll</p>
        }
    </div>
</div>


<div id="Pop_up" style="display:none">
    <p>Seleziona di chi sarà la responsabilità di questa penale</p>
</div>
@section scripts {
    <script type="text/javascript">


        function isConQRadioFilter(element) {
            // Create radio buttons for filtering boolean values
            var html = `
            <label>
                <input type="radio" name="isConQFilter" value="true" /> CONQ
            </label>
            <label>
                <input type="radio" name="isConQFilter" value="false" /> Ritardo
            </label>
        `;
            // Append the radio button HTML to the filter container
            element.append(html);

            // Trigger filtering when a radio button is clicked
            element.find("input[type=radio]").change(function () {
                var filterValue = $(this).val();
                var grid = $("#grid").data("kendoGrid");
                grid.dataSource.filter({
                    field: "isConQ",
                    operator: "eq",
                    value: filterValue === "true" // Convert the value to a boolean
                });
            });
        }

        function onEdit(e) {


        }

        function excelExport(e) {
            var sheet = e.workbook.sheets[0];
            var template2 = kendo.template(e.sender.columns[2].template);
            var template3 = kendo.template(e.sender.columns[3].template);

            var data = e.data;
            for (var i = 0; i < data.length; i++) {
                sheet.rows[i + 1].cells[2].value = template2(data[i]);
                sheet.rows[i + 1].cells[3].value = template3(data[i]);
                if (data[i].isConQ) {
                    sheet.rows[i + 1].cells[4].value = "CONQ";
                } else {
                    sheet.rows[i + 1].cells[4].value = "Ritardo";
                }

            }
        }



        function descriptionTemplate(data) {


            if ((data.ddl_stato.Text == "INLAVORAZIONE" || data.ddl_stato.Text == "NEGOZIATA")  && data.ddl_Responsabilita.Text != null) {
                return data.ddl_Responsabilita.Text;
            }
            else {
                return "";
            }
        }


        function typeTemplate(data) {

            var html;
            if (data.isConQ) {
                html = kendo.format(
                    "<a class=\"k-button\" href='" + '@Url.Action("Create_Penale_CONQ", "Summary")' + "/" + data.Id + " '>CONQ</a>  ",

                );
            } else {
                  html = kendo.format(
                    "Ritardo ",

                );
            }
            return html;
        }

        //(function () {
        //    isConQFilter("ciao");
        //})();

            function isConQFilter(element)
            {
                console.log("isConQFilter called");
                element.kendoDropDownList({
                    dataSource: [
                        { text: "CONQ", value: true },
                        { text: "Ritardo", value: false }
                    ],
                    dataTextField: "text",
                    dataValueField: "value",
                    optionLabel: "-- Seleziona Tipo --",
                    valuePrimitive: true
                });
            }


            //function isConQFilter(element) {
            //    debugger;
            //    console.log("isConQFilter called");

            //}
    </script>
    }
    <style>
        .ellipsis {
            overflow: hidden;
            text-overflow: ellipsis;
            display: -webkit-box;
            -webkit-line-clamp: 2;
            -webkit-box-orient: vertical;
        }


        .k-grid-header .k-header {
            height: 20px;
            padding: 0;
        }

        .k-grid tbody tr {
            line-height: 14px;
        }

        .k-grid tbody td {
            padding: 1px;
        }
    </style>


the coulm i'm talking about is the "isConq" one, i would like to show "Conq" or "Ritardo" instead of "è vero" or "è falso".

Following the doc, i'm calling the "isConQFilter" js function, but it is never triggered by the kendo.

Where am i wronged?

If you need something else, please, tell me.

I'm using kendo mvc grid version 2016.