How do you make a Restricted Gui/VIP Button?

Hi, I tried making a button that only morphs you if you have a special gamepass/badge. (I will change it to a badge later) I made this script:

local player = game.Players.LocalPlayer
local gamepass = 915027207

function morph()
--censoring just so nobody steals ;-;
end

script.Parent.MouseButton1Click:connect(function()
	local allow = (
		game:GetService('MarketplaceService'):PlayerOwnsAsset(player.userId, gamepass) or
		game.CreatorId == player.userId
	)
	if allow then
		morph()
	else
		script.Parent.Text = "Not enough Points!"
		script.Parent.TextColor3 = Color3.new(255,0,0)
		wait(1)
		script.Parent.Text = script.Parent.Name
		script.Parent.TextColor3 = Color3.new(0,0,0)
	end
end)

but I get this error "Unable to cast value to Object" and the button results in doing absolutely nothing. Please help!