I followed the tutorial by @griffpatch and made a project. It took me over 2 hours to use the tutorial, so if you don't have the time, this is a quick shortcut.
You might have seen my new project Scratch Multiplayer E13 + Multiplayer, which is Episode 4 of the Cloud Multiplayer tutorial that @griffpatch has. Here is the tutorial from episodes 1 - 3, so you can impleted this into any game.
