Your Windows version is too old (pre-1809) or missing the Universal Windows Platform runtime.

Then fetch the matching Appx (x64 for 64-bit Windows, x86 for 32-bit).

Microsoft hosts an official listing for the framework:

Install the latest Windows updates. Minimum required: Windows 10 October 2018 Update (1809). Upgrade to Windows 10 22H2 or Windows 11.

Yes, when downloaded from Microsoft (Store, NuGet, Visual Studio, or ADK). It is a digitally signed Microsoft component.