How do I invite mine steam brethren?

I have a friend on steam whomst just bought the game, I make an exhibition lobby, and I find no way to invite him.

Steam doesn’t allow invite, can’t invite him in game cuz it just pulls up my Xbox friends list, and uh… I cannah figure it out

You can’t invite them yet. The only way to play against them is either on the steam version, or make a lobby and hope they join yours. Set specific settings and player count and it’s pretty easy to have it work but just a pain.