What's wrong with this code?

So, I'm trying to force a Prompt Purchase, if someone doesn't have a gamepass, but if they do, they can access a place. I've finished my code, but it just doesn't want to work.

service = game:GetService("MarketplaceService")
teleportService = game:GetService("TeleportService")
placeID = 11111111
gamepass = 237848679

game.Players.PlayerAdded:connect(function(onPlayer)
    if service:PlayerOwnsAsset(onPlayer, gamepass) then
        teleportService:Teleport(placeID, onPlayer)
    else
        service:PromptPurchase(onPlayer, gamepass)
    end
end)