2 player online co-up on the same console

I have spent hours trying to figure out how to play together on the same team with my son against other players online when we both are on the same console. We both have EA accounts/users linked to PSN accounts and where one is the primary and have an EA online license. I am able to send an invite to play an online co-up game but the other user is not able to accept the invite as we are both on the same console. Can someone please explain how this is supposed to work? It's really frustrating that a 2 player online game is so incredibly difficult to figure out on this new FC 26 game.