I know of the invite command that invites yourself to other rooms… talk about party crashing. But I have yet to see a command to invite others.
What you can do, is set up a link to your room and give the link to others. You should read Dave’s posts in Java forum. There are commands to set your room up and then also to register other chatters for your room.
That is all I can tell you.
I am guided by a force more powerful than luck.