index.razor

@page "/"
@using TodoListApp.Data
@inject IJSRuntime JsRuntime;

<EditForm Model="@usernameFormModel" OnValidSubmit="@HandleValidSubmit">
    <DataAnnotationsValidator />
    <ValidationSummary />

    <InputText id="name" bind-Value="@usernameFormModel.Username" />
    <button type="submit">Fetch Repositories</button>
</EditForm>

@functions {
    private UsernameFormModel usernameFormModel = new UsernameFormModel();

    private async Task HandleValidSubmit() {
        await JsRuntime.InvokeAsync<int>("alert", usernameFormModel.Username);
    }
}