I learned that changing the app install location setting can make the games installed to an external SSD from this article.

https://windowsloop.com/install-xbox-game-pass-games-in-another-drive

But then all my apps, even non-games, will be installed in this external SSD which I do not want.

So I want to find a way 'only' Xbox PC games are installed in the external SSD and all the other apps are installed in the C drive as a default.