Go to your Library > Right-click the game > Manage > CD Keys . This is the code you need to copy into the Rockstar Launcher.
Websites may advertise "hot" or discounted keys that turn out to be free upon deeper inspection (often a lure). rockstar games launcher activation code free hot
If valid, click to permanently link the game to your library. 5. Troubleshooting: "Activation Code Already in Use" Go to your Library > Right-click the game > Manage > CD Keys