I can't detect if a player has a gamepass and Roblox isn't telling me the problem?

I am making a stereo gamepass for my game and I pulled this from the Roblox wiki but it doesn't say what the problem is. Here is the code:

local passId = 720949646
 
function isAuthenticated(player)
    return game:GetService("MarketplaceService"):PlayerOwnsAsset(player, passId)
end
 
game.Players.PlayerAdded:connect(function(plr)
    if isAuthenticated(plr) then
        local stereoclone = game.Workspace.Stereo:Clone()
		stereoclone.Parent = plr.Backpack
    end
end)

Thank you :)