How can I load a dialog on demand?

[index.razor]

@page "/"

@using BlazorApp.Data
@inject WeatherForecastService ForecastService

<h3>Dialog</h3>
<button class="btn btn-primary"
        @onclick="OpenDialog">
    Open Dialog
</button>
@if (ShowPopup)
{
    <!-- This is the popup to create or edit a forecast -->
    <div class="modal" tabindex="-1" style="display:block" role="dialog">
        <div class="modal-dialog">
            <div class="modal-content">
                <div class="modal-header">
                    <h3 class="modal-title">Modal Dialog</h3>
                    <!-- Button to close the popup -->
                    <button type="button" class="close"
                            @onclick="ClosePopup">
                        <span aria-hidden="true">X</span>
                    </button>
                </div>
                <!-- Edit form for the current forecast -->
                <div class="modal-body">
                    <input class="form-control" type="text"
                           placeholder="Celsius forecast"
                           @bind="forecasts[0].TemperatureC" />
                    <input class="form-control" type="text"
                           placeholder="Summary"
                           @bind="forecasts[0].Summary" />
                    <br />
                    <!-- Button to save the forecast -->
                    <button class="btn btn-primary"
                            @onclick="Save">
                        Save
                    </button>
                </div>
            </div>
        </div>
    </div>
}
@code {

    private WeatherForecast[] forecasts;

    protected override async Task OnInitializedAsync()
    {

        forecasts = await ForecastService.GetForecastAsync(DateTime.Now);
    }
    bool ShowPopup = false;
    void OpenDialog()
    {
        // Open the Popup
        ShowPopup = true;
    }
    void ClosePopup()
    {
        // closes the Popup
        ShowPopup = false;
    }
    void Save()
    {
        //closes dialog after the save execution
        ShowPopup = false;
    }
}