WorldSettings asset is used by HoloFair to setup multiplayer settings for the world you are creating as well as initialize the portals you have created. To create the WorldSettings right click anywhere in the project window or where you prefer then Create -> HoloFair -> WorldSettings. See the GIF below:
After that make sure to assign entry scene, portals prefab, preferable max amount of spectators, players, room variables and Area Of Interest. It is recommended to use following default settings for most cases:
Once this is done, you are almost ready to build, compile, and host addressables as well as make your world live on HoloFair.