Use of GaussianBlurEffect in Winui 3 and CommunityToolkit.WINUUI.UI version 8

How can use GaussianBlurEffect in WINUI 3 and CommunityToolkit.WINUI,UI versione 8?

public static CompositionEffectBrush CreateBlurEffectBrush(double amount = 0.0)
{
    var effect = new GaussianBlurEffect
    {
        Name = "Blur",
        BlurAmount = (float)amount,
        Source = new CompositionEffectSourceParameter("source")
    };

    var compositor = App.MainWindow.Compositor;
    var factory = compositor.CreateEffectFactory(effect as IGraphicsEffect, new[] { "Blur.BlurAmount" }); // Cast to IGraphicsEffect
    var brush = factory.CreateBrush();
    brush.SetSourceParameter("source", compositor.CreateBackdropBrush());
    return brush;
}

You need to install the Microsoft.Graphics.Win2D NuGet package.

Then make the MainWindow accessible.

App.xaml.cs

using Microsoft.UI.Xaml;

namespace WinUIApp;

public partial class App : Application
{
    public App()
    {
        InitializeComponent();
    }

    public static Window MainWindow { get; } = new MainWindow();

    protected override void OnLaunched(LaunchActivatedEventArgs args)
    {
        MainWindow.Activate();
    }
}