How to implement server side logic with PHOTON?

Good day. I'm making turned based game with the photon networking solution. I have a GameLogic script on one of the clients that calculates all the the game events. However I need that script to be executed server side because otherwise if the player with the GameLogic script leaves the game will not work. My question is simple. How do I make this script execute server side? Has anybody else done anything similar? Could you guys be specific on how to implement this? Thanks. ~Alexander