Why is GetPlayerPlaceInstanceAsync erroring?

So I'm trying to use GetPlayerPlaceInstanceAsync to see if a player has friends who are playing the same game. On the local script, a RemoteFunction is called to get a list of friends who are playing the game. It's passing Player:GetFriendsOnline() as the argument and in the server, GetPlayerPlaceInstanceAsync is called to check if each of the friends are playing the game.

But in Studio, I keep getting this error:

TeleportService::GetPlayerPlaceInstanceAsync can only be called from the server.

and on real servers, I'm getting this error on the line that's invoking the RemoteFunction:

HTTP 0(HTTP 400 (HTTP/1.1 400 TargetPlaceNotPartOfCurrentGame))

I do have HTTP Service enabled.