While you can launch games not purchased from Steam in its desktop app, games from the Microsoft Store or PC Game Pass need a little help to work.

Launch Steam on your computer to add your non-Steam games to your Steam library. Once it’s up and running, navigate to the top of the window and click on the Games tab.

Open the Steam application in desktop mode and follow the same steps as you would on a PC: go to Games > Add a Non-Steam game to my Steam Library, select the game, and add it to your library.

See how you can add Steam game shortcut to the Start Menu. You can pin Steam games to Taskbar or Desktop in Windows 11/10 by following this trick.

How do you add non-Steam games to your Steam library? Steam’s library system is streamlined and easy to use provided you don’t subsist on Uplay points or posses a wealth of DRM-free gems ...

Steam has most PC games, but it doesn't have them all. You'll need to know how to add external games to your Steam library to have your collection in one spot.