If you decide to create a multi user scene using Photon, you will first need to register with Photon for that particular project, create an application on their Cloud server, and copy paste that application Id in the Photon set up wizard to start working. That project will be then tights to your photon appid.
Open this Photon Set up Wizard with the menu: "PlayMaker/Photon/Set up Photon Networking" OR "Window/Photon Unity Networking"
1: Initial setup
If you are not yet set up, Click on the orange button "set up", else jump to step 4 below.
2: Connect to Photon Cloud
You are presented with two options.
A: If it is the first time you are going to work with playmaker, you can get access to a free app trial for 30 days,
Simply put your email address and click "send", photon will grant you with an appId.
B: You are already registered with Photon, and you do have an appId available already. Click on "setup"
3: Save connection settings
Once you have this appId, Click "Save", and then "Close setup"
4: Project with Photon connection active
If Photon Server is set up properly, it will be shown in green. If not, and you actually went trough that set up, please contact us for assistance via the PlayMaker forum.
You can always click on Setup to modify the appID or your registration and server settings.
The next step is to set up the scene itself.