@inject IJSRuntime js

<p><label for="foo-id">Label for Blazor Upload</label></p>

<TelerikUpload Class="foo-id"
               @ref="@MyUpload"
               Multiple="false">
</TelerikUpload>

<!-- Allow the <script> tag to reside here in the Razor file for this workaround -->
<script suppress-error="BL9992">function addUploadId(uploadClass) {
    var uploadInput = document.querySelector("." + uploadClass + " input");
    if (uploadInput) {
        uploadInput.setAttribute("id", uploadClass);
    }
}</script>

@code {
    TelerikUpload MyUpload { get; set; }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (firstRender)
        {
            await js.InvokeVoidAsync("addUploadId", MyUpload.Class);
        }
        await base.OnAfterRenderAsync(firstRender);
    }
}