INSTALL XBOX
Download the Legacy version though the Xbox app
Then Download FiveM exe
Download Steam if you haven't
Once GTA is installed, find the GTA Legacy folder in the xbox games folder will be located with in the C Drive
Then Finds the Steam - Steam folder in the C Drive and move the complete GTA folder from xbox to the steam folder.
Then run and install FiveM and it will ask where the location is got the GTA.exe Find it in the steam folder and it will then link the game and ask for an update when successful.
Please note you also need Rockstar Launcher installed.
I hope this helps and works for you like it did for me
some good servers
STRP
Citylife
Ldn london