If you have Live PLayers or All Players selected, you’re already as “multiplayer” as it gets, really.
Multiplayer in MSFS has serious limitations:
- You can’t communicate with other players via the sim
- Each player has their own ATC that’s oblivious to other live players
- You can’t see custom liveries unless you also have them installed
- You’ll see generic plane models if you don’t have the same 3rd party planes others have
- You can’t see other planes’ tail numbers
- If you’re using AI traffic (vs Live Traffic), each player will see completely different AI planes.
- Ground vehicles, planes and personnel will be unique to each player.
Best you can do it team up with someone on Discord or some other chat program and fly with them.