I have read the same issues and I found it will need to install WinRT C++ library .
I have installed the WinRT C++ library from both vsix and Nuget. It still get the same errors.

Please refer to #489. It also looks like you're using VS2019, so #565 might have some help in it as well.
Try this one:
Adding a project reference in TerminalApp to the TerminalSettings project.