<TelerikButton OnClick="@ToggleStep">Toggle attachments step visibility</TelerikButton>

<TelerikWizard @bind-Value="@CurrStepIndex">
    <WizardSteps>
        <WizardStep Label="Personal Details" Icon="user">
            <Content>
                content here
            </Content>
        </WizardStep>

        @if (AttachmentsStepVisible)
        {
            <WizardStep Label="Attachments" Icon="paperclip">
                <Content>
                    conditional content here
                </Content>
            </WizardStep>
        }

        <WizardStep Label="Confirmation" Icon="check">
            <Content>
                other content here
            </Content>
        </WizardStep>
    </WizardSteps>
</TelerikWizard>


@code {
    bool AttachmentsStepVisible { get; set; }

    int CurrStepIndex { get; set; }

    void ToggleStep()
    {
        // defence against hiding the step when it is the last step, which would cause an exception
        if(AttachmentsStepVisible && CurrStepIndex == 2)
        {
            CurrStepIndex = 1;
        }
        //the actual visibility toggle
        AttachmentsStepVisible = !AttachmentsStepVisible;
    }
}