How to set max players that join the game using photon Bolt?

Hello , iam making a new game , and thats gonna be my first online game development .
i want to make 1 vs 1 online multiplayer game with 3 rounds , that means 1 Server = 2 Client (players) and the players playes 3 rounds .
the problem is that i cant set the limit of players that join the Server.
all Photon Bolt Video Tutorials and Docs doesn,t help and dont have details info to do that.

Can anyone help me ?