How to startup desktop app main window in maximum size

[Tad29Eng]

I create desktop app, how to startup main app window in maximize size (same as pressing maximize button in window)

[Tad29Eng]

I try use in App.xaml.cs

 var presenter = (OverlappedPresenter)MainWindow.AppWindow.Presenter;
 presenter.Maximize();

but this not worked, when app runing exception thrown: System.NullReferenceException Microsoft.UI.Windowing.OverlappedPresenter.Maximize()