API_URL is still accepted for BC compatibility of the self-hosted deployments.
This will allow deploying on a single domain, using a reverse proxy that acts on the path.
This however means that the config needs to be changed for all WorkAdventure deployments.
In "alone" mode (or single-player mode), WorkAdventure does not connect to the server at all.
In order to enter the "alone" mode, you need to add "?alone=true" to the URL.
"alone" mode can be useful for tutorials (First Time User Experience) where you want to explain how WorkAdventure works without being disturbed by other users.
