Game teleport script on chat not working?

This script WAS working, until I added the GUI configuring parts to the script. This script is supposed to teleport the player to R2D when they chat "r2d" (With :lower()) This script is a regular script in a GUI:

game.Players.PlayerAdded:connect(function(plr)
	plr.Chatted:connect(function(msg)
		msg = msg:lower()
		if msg == "r2d" then
			script.Parent.TpName.Visible = true
			script.Parent.TpTo.Visible = true
			script.Parent.Frame.BackgroundTransparency = 0.8
			wait(1)
			script.Parent.Frame.BackgroundTransparency = 0.6
			wait(1)
			script.Parent.Frame.BackgroundTransparency = 0.4
			wait(1)
			script.Parent.Frame.BackgroundTransparency = 0.2
			wait(1)
			script.Parent.Frame.BackgroundTransparency = 0
			wait(2)
			game:GetService("TeleportService"):Teleport(147513144,plr) -- I didn't put the real R2D ID here. It's just a random ID to test this.
			
		end
	end)
end)

Your script never checked against players that joined before the script started. Also, it's checking against all players even though it's only meant to check against one.

Here's my solution:

A script in workspace or ServerScriptService:

local Players=game:GetService("Players")
local TeleportService=game:GetService("TeleportService")
local GameID=163612261

function OnPlayerAdded(Player)
	-- add events to players
	local Event=Player:FindFirstChild("OnPlayerTeleporting")
	if not Event then
		Event=Instance.new("RemoteEvent",Player)
		Event.Name="OnPlayerTeleporting"
	end
	
	-- chat hook
	Player.Chatted:connect(function(Message)
		if Message:lower()=="r2d" then
			wait(1)
			TeleportService:Teleport(GameID,Player)
		end
	end)
	
end

Players.PlayerAdded:connect(OnPlayerAdded)

-- handle players connected before the script loaded
for i,v in pairs(Players:GetPlayers()) do
	OnPlayerAdded(v)
end

A localscript in a screengui, with a frame:

-- localscript in a playergui that contains a frame - handles gui animations only
local Gui=script.Parent
local Frame=Gui:WaitForChild("Frame")
local Player=game:GetService("Players").LocalPlayer
local Event=Player:WaitForChild("OnPlayerTeleporting")

Event.OnClientEvent:connect(function()
	for i=1,0,-0.1 do
		Frame.BackgroundTransparency=i
		wait(0.1)
	end
end)