Make sure you have a legal copy of Grand Theft Auto V installed on your PC
Close GTA V and Steam/Epic Games/Rockstar Launcher if they are open
Go to the official FiveM website
Download the FiveM installer
Run the downloaded installer
Allow the installer to download required files
Select the GTA V installation folder when prompted
Wait for the installation to complete
Launch FiveM
Sign in if required
Let FiveM update and verify files
Join a server or add a server to favorites