How do you make a gamepass so when a player buys it they wear a hat when they join the game?

Im trying to make a gamepass that makes it when a player buys it they wear a hat when they join the game but i cant get around his problem i tried fixing the script but i think i just made it worse since im a beginner at scripting.

local MarketPlaceService = game:GetService('MarketplaceService')
local GamepassId = 11001479

game.Players.PlayerAdded:Connect(function(PlayerWhoJoined)
	PlayerWhoJoined.CharacterAdded:Connect(function()
		if MarketPlaceService:UserOwnsGamePassAsync(PlayerWhoJoined.UserId, GamepassId) then
			local BetaHat = script:FindFirstChild('Accessory'):Clone()
			BetaHat.Parent = PlayerWhoJoined.Character
		end
	end)
	MarketPlaceService.PromptGamePassPurchaseFinished:Connect(function(Player,GamePassId,Purchased)
		if GamePassId == GamepassId and Purchased == true then
			local BetaHat = script:FindFirstChild('Accessory'):Clone()
			BetaHat.Parent = PlayerWhoJoined.Character
		end
	end)
end)