Depending on the version of the Terror mod menu users have downloaded, the installation steps might be different, but generally, they have to download the file and then run it.

Thanks to a cool new mod, Minecraft players have the opportunity to enjoy a flashy, fully-animated main menu when starting up the game.

The use of mod menus in GTA Online is considered cheating, which goes against the game's code of conduct. Therefore, if players are discovered using mod menus, they will get banned.