Grand Theft Auto V is available on ONMO+ through Install & Play (it is not included with Essential Pass).
Requirements
An active ONMO+ subscription.
Grand Theft Auto V purchased and owned in your Steam library (ONMO+ does not sell the game).
Your Steam account linked to ONMO+. For setup steps, see How do I set up Steam and start playing my own games?.
Story Mode only
Only Story Mode (Single Player) is supported. GTA Online is not currently available on ONMO+.
Rockstar Games Launcher sign-in
On your first launch, you will need to sign in to your Rockstar Games account before you can play. This is a one-time step.
Settings window on repeat launches
Display settings, in-game settings, shader compilation, or game agreements may appear on repeat launches. This is normal — make your selections or wait for the process to complete before playing.