How to create turn base system for tic tac toe game with PUN

I'm doing the multiplayer tic tac toe game on inity. I already made the intelligence system against the bot. But now I plan to do multiplayer. I'm using photon network. I don't know where it starts. I need to make the system to check which is the player's turn to play.

I read the PunTurnManager class in this article https://doc.photonengine.com/en-us/pun/v1/demos-and-tutorials/package-demos/rockpaperscissors-demo But I don't know how to implement the script in my game.

Can you help me?