Getting Error In installing Nuget Package Microsoft.UI.Xaml in window 10 ver 1903 and visual studio 2019

I want to work xaml Islands in a WPF project and need to install Microsoft.UI.Xaml. My windows version is 1903 and am using visual studio 2019.But I get the error :

   Microsoft.UI.Xaml nuget package requires TargetPlatformVersion >= 10.0.18362.0 (current project is -1)