Tournament info

So we are currently running tournie tests and I have a few questions before we run a live trial

1. How can the system determine who is playing who and where does it show this to everyone?

2. How do users know their tournament counterparts name on the given platform chosen for the game?

3. Where would it show the bracket selection for who has to face who with these details? My users are saying that they don’t have to add usernames for xbl, steam or PS4