Yes http service is allowed, its a experience and teleports u to a place. But would it have to be put in the actual experience to ensure it lets u teleport to the place? I made it on a separate testing game.
I have tried using :Teleport() however it didnt work.
If it is enabled then maybe that game is private? or archived? either way one more solution is:
Go to the place → File → Publish To Roblox As → Game Name → Add as a new place
If TeleportAsync and Teleport fails to teleport the player, and they have the same or similar error (which says that the place is restricted), then the only solution is to VERIFY that the original place and the teleporting places have enabled Allow Third Party Teleports.