Why win't this script show a GUI for donators and admins?

This is a script that will show if you donated or a admin but it won't work. Please help.

local mps = game:GetService("MarketplaceService")
local id = 971534148

script.Parent.MouseButton1Click:Connect(function(player)
	mps:PromptProductPurchase(game.Players.LocalPlayer,id)
	if mps:UserOwnsGamePassAsync(player.UserId, id) then
		script.Parent.Parent.Parent.Parent.DonatorsandAdminsGUI.MainFrame.Visible = true
	else
		script.Parent.Parent.Parent.Parent.DonatorsandAdminsGUI.MainFrame.Visible = false
	end
end)

Thanks.