Dear Leon,
sorry for delaying, i was sick.
thanks for your answer, i found a pretty simple solution to solve my problem:
<?xml version="1.0" encoding="utf-8" ?>
<xct:Popup xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:xct="clr-namespace:Xamarin.CommunityToolkit.UI.Views;assembly=Xamarin.CommunityToolkit"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="TestPage">
<xct:Popup.Content>
<StackLayout Padding="{OnPlatform iOS=-27, Android=0}">
<Label Text="Hello Content Popup Page"></Label>
</StackLayout>
</xct:Popup.Content>
</xct:Popup>