When creating Desktop-Bridge ("Centennial") apps, we sometimes need to reference winmd files manually by using "browse". If we're Targeting a certain version T of Windows 10, with Minimum version M, but we're developing it on a Computer with version C. Which one of the winmd files should we target? T, M, or C? Does the file need to exist on the users' machines?
If you are targetting version 'T' you need to have the Windows SDK for version 'T' installed. Then reference the windows.winmd for that version.
Follow the adaptive coding guidelines to ensure your app works correctly on your minimum version 'M': https://learn.microsoft.com/en-us/windows/uwp/debug-test-perf/version-adaptive-code
Needless to say you should also test your app on a device running OS version 'T', not only on your dev machine running OS version 'C'.
As an aside, from a forward looking perspective, you also might be interesting in learning about this preview: https://blogs.windows.com/windowsdeveloper/2019/04/30/calling-windows-10-apis-from-a-desktop-application-just-got-easier/