In Windows 10, your toast notification content is described using an adaptive language that allows great flexibility with how your notification looks. This package allows you to create toast notifications without using XML, and also allows desktop apps to send toasts. Set your TFM to net5.0-windows3.0 or greater. NET 5 apps must use one of the Windows 10 TFMs, otherwise the toast sending and management APIs like Show() will be missing.
NET Core 3.1, otherwise the APIs will be absent. In your project, right-click on 'References', and click 'Migrate nfig to PackageReference'. NET Framework desktop apps that still use nfig must migrate to PackageReference, otherwise the Windows 10 SDKs won't be referenced correctly.