TeleportService:TeleportToPrivateServer() not working. How do i fix?

my problem is, is that it wont reserve the server. I don't know how to fix this, but I checked the dev wiki and i didn't see a mistake. Heres the code, I really hope you can help.

while wait() do
	if game.ReplicatedStorage.SoloPlayers.Value == 2 then
		if tpsolo.Value == false then
			tpsolo = true
			local key = ts:ReserveServer(3210889612) --error here
			local players = {}
			for i, v in pairs(game.ReplicatedStorage.SoloPlayers:GetChildren()) do
				local plr = game.Players[v.Value]
				table.insert(players, plr)
			end
			wait(.15)
			ts:TeleportToPrivateServer(3210889612, key, players)
			wait(1.5)
			tpsolo = false
		end
	end
end

i did not have HTTP on.