If menyoo doesnt work for u watch this vid

Hi i just bought gta 5 a few days ago on the pc because i wanted to mod,
So i'm new to this. I tried installing menyoo in C:\Program Files\Rockstar Games\Grand Theft Auto V, i already installed open iv and scripthook, but when i launch the game and i press f8 it doesnt seem to work. can somebody help me or tell me what im doing wrong. when i try to go online it says that i have an altered game does this have to do with anyting?I have it on the rockstarlauncher and im running the latest version.