You don't use that with a server - that's for when you're playing and want someone else to join you locally.
#BMC5 Luna Error
devout rain
Being able to even see the "Share World" button while connected to a server sounds like a bug - may want to report that to LunaPixel in their Discord.
hardy grotto
i used it last night, it gives you a server ip for your friend.
devout rain
It lets a friend join your game.
When you're on a server, even if you own the server, it isn't playing locally so it's not "yours" in the same respect.
So if you used it last night on single player, then hit it today while connected to your BisectHosting server, it would work last night but not today.