If you purchased RDR2 on another storefront, you do not need to hunt for the executable manually. The platforms will generate it for you:
Even if a third-party download appears to work initially, it will lack the ability to receive official updates. As Rockstar releases patches and new content, your modified launcher will become incompatible, leading to crashes, missing features, or complete inability to launch the game.
If you need to find the specific RDR2.exe to manage mods or set administrative permissions: Rockstar Games Launcher
Run RockstarGamesLauncher.exe to reinstall the program. Log In: Sign in with your Rockstar Social Club account.
: Right-click RDR2 in your Library > Properties > Installed Files > Verify integrity of game files .