How do I prompt game pass purchase only to users who haven't purchased yet?

Hey scriptinghelpers, just wondering how do I prompt a game pass purchase only to users who haven't purchased it yet? The code provided below is what I'm using, it work's even with the prompt purchase. I was wondering how I would prompt the game pass purchase only to users who have not purchased it yet? I have been referring to the MarketplaceService link https://developer.roblox.com/en-us/api-reference/class/MarketplaceService for help with this but, can't seem to find exactly what I'm looking for there so I thought I might as well ask for help. As I always say I'm only here to learn! Thank you for the help in advance, I appreciate it.

This is a Script inside of a Part inside of Workspace.

--did some editing
local debounce = true
local MarketplaceService = game:GetService("MarketplaceService")
local GamepassId = 17468467
script.Parent.Touched:Connect(function(hit)
	if debounce == true and hit.Parent:FindFirstChild("Humanoid") then
		local character = hit.Parent
		local player = game:GetService("Players"):GetPlayerFromCharacter(character)
		MarketplaceService:PromptGamePassPurchase(player, GamepassId)--where im prompting purchasing currently (prompts everyone on touch)
		if player and MarketplaceService:UserOwnsGamePassAsync(player.UserId, GamepassId) and player.leaderstats.Tix.Value >= 666 then
			debounce = false
			local avatar = character:GetChildren()
			for _,t in pairs(avatar) do
				if t.ClassName == "Part" then
					local fire = t.Fire
					fire.Color = Color3.new(1,0,0)
					fire.SecondaryColor = Color3.new(0,0,0)
--tried using else here, only worked if player already owned the game pass
				end
			end
		end
		wait(1)
		debounce = true
	end
end)
--let me know if you need me to add any more comments about what I've done and am trying to do