Currently the GeForce NOW app does not indicate which games are on PC Game Pass. To verify if a game is currently available on PC game pass, members should visit https://www.xbox.com/en-us/xbox-game-pass/games#.
The GeForce NOW app will highlight new and popular supported PC Game Pass games in the “PC Game Pass” row in the GeForce NOW app.
Note: Supported Xbox PC Game Pass games will be automatically added to "My Library" when connecting your account in GeForce NOW settings. Members will need to press RESYNC from the settings menu to have new games added to "My Library".