Are there any tutorials available for Photon Chat itself? There are only two Photon tutorials on Scirra (both excellent but neither covers chat extensively).
The Demo's from 
ThePhotons included with the Photon plug-in just aren't helpful as they have no instructions/comments whatsoever. The demo-chat.capx doesn't seem to function at all, of course I'm sure I'm doing something wrong, but without instructions how would I know?
I'm having real issue trying to do something as seemingly simple as having sent messages display the unique name of each user in the simplified chat room of this tutorial... https://www.scirra.com/tutorials/5023/how-to-build-a-multiplayer-game-with-photon
Its frustrating because this is the type of thing that Constructs Multiplayer plug-in handles very simply, but without IOS support (where much of my client base is) I have to use Photon
Hope I can help you with this
1. First you must set optional user id for the user unique name display
2. Subscribe the channel you want to (this action mean the user join to the roomchat)
3. Use publish message for send user typed text
4. Update your textbox for display the coming chat using "On Message in Channel" action, with
Textbox.text &PhotonChat.Sender& ": " &PhotonChat.Message &Newline[/code:1u85ctmg]