Add a callback that's ran before a player joins the world.
This callback returns a promise and the player won't join
until that promise is resolved. If the promise is not
resolved within a reasonable time, the player joining will
be rejected. If the player joining leaves/disconnects, then
the event data's isValid will return false.
Remarks
Add a callback that's ran before a player joins the world. This callback returns a promise and the player won't join until that promise is resolved. If the promise is not resolved within a reasonable time, the player joining will be rejected. If the player joining leaves/disconnects, then the event data's isValid will return false.