How to enable a certain GUI if the player has a game pass?

So I've been working really hard and i just can't figure out how to enable a certain GUI if the player has a gamepass? here's my script

local plr = game.Players.LocalPlayer

local gamepassid = 5509969
game.Players.PlayerAdded:Connect(function()
	while wait(0.2) do 
	if game:GetService("MarketplaceService"):UserOwnsGamePassAsync (plr.UserId, gamepassid) and print("Got gamepass") then
	game.ReplicatedStorage.Events.enabler:FireServer()
	
end
end
end)

here's the onserverevent script

local plr = game.Players.LocalPlayer
game.ReplicatedStorage.Events.enabler.OnServerEvent:Connect(function()
	
	plr.PlayerGui.Trail2onoff.Enabled = false
	script.Parent.Trail2onoff.Enabled = false
end)

I would really appreciate your help! Also there is no error

Here are some very important things to remember whilst scripting:

• You can only access LocalPlayer (game.Players.LocalPlayer) from a LocalScript.
• You cannot edit a players GUI from a server script, as you have done from the "onserverevent script" (this is wrong). You can only edit GUI from a LocalScript.

With your script, you have completely messed up here so I'm just gonna rewrite it and consequently, as a bonus, give you good ways to organise scripts!

SERVER SCRIPT:

local MarketPlaceService = game:GetService("MarketPlaceService")
local RemoteEvent = game.ReplicatedStorage.RemoteEvent -- create a RemoteEvent first!
local GamePasses = {
	GamePassNameHere = 5509969
	-- insert other game passes here
}
local GamePassNameHere = {}
-- create more local variables like this for each gamepass


game.Players.PlayerAdded:Connect(function(player)
	local UserId = player.UserId
	
-- retrieve the data here THEN continue to doing the gamepass stuff	

	GamePassNameHere[UserId] = MarketPlaceService:UserOwnsGamePassAsync(UserId,GamePasses.GamePassNameHere)
	
if GamePassNameHere[UserId] then
    		RemoteEvent:FireClient(player,"GamePassNameHere")
	end
end

CLIENT SCRIPT (LOCAL SCRIPT):

local RemoteEvent = game.ReplicatedStorage.RemoteEvent
local player = game.Players.LocalPlayer
local playerGui = player:WaitForChild("PlayerGui")

RemoteEvent.OnClientEvent:Connect(function(tag)
	print("Remote Event Received: "..tag) -- telling you that you received the event
	if tag == "GamePassNameHere" then
		playerGui.Trail2onoff.Enabled = false -- whatever gui you want to enable/disable
		playerGUI.moreguihere.Frame.Visible = true
		-- etc

	elseif tag == "you can write more event's here if you want" then
		-- do stuff
	end
end)

And that's it! Leave me an upvote or whatever if it was a good answer :) and if you see an error and/or have any questions i'll be glad to edit/answer.