https://learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt/microsoft.ui.xaml.controls.itemspresenter.headertemplateproperty?view=windows-app-sdk-2.0
ItemsPresenter.HeaderTemplateProperty Property (Microsoft.UI.Xaml.Controls) - Windows App SDK |...
Identifies the HeaderTemplate dependency property.
windows apppropertymicrosoftuixaml