You need public score server and it must be run before game starts.
You need Photon's AppID and ChatAppID. Put in them to "/Assets/Photon Unity Networking/Resources/PhotonServerSettings".
Select your closest region. It's just recommendation. I live in South Korea, so I used "Kr" region.
Change URL that Http requests.
Fixed Bugs (17.08.13)
Game Over occurs even some of player still alive.
Can't rotate screen after try to chat in Inspector mode.
Zombies were didn't sync properly.
Refund money when revives
Freezing issue when player dies
Respawn protection didn't worked
About resources (License)
You can use any script in this game, but don't use blood effect and weapon models. Blood Effect is sales on Unity Asset Store, and it's not my resource so you could have disadvantage or might be subject to legal regulations. Weapon models are from https://www.cgtrader.com/, I used free models but I'm not sure they can use for commercial purpose.
I'm strongly recommend that just learn how this game works, not gonna use the resources. I'm not responsible of those personal un-licensed uses!