Dubbed 'Remote Play Together', this new Steam feature will allow players to enjoy local multiplayer games online "just like handing a second controller to a friend". Moreover, only the host needs to own the game and can thereby send invites to Friends via the Steam Overlay.
https://forum.unity.com/threads/stea...he-box.758171/
Source
https://forum.unity.com/threads/stea...he-box.758171/
Source