Screen Gui tweening but not appearing?

local Part = game.Workspace.Shop
local Gui = game.StarterGui.BackpackShopGui.Frame
local TweenService = game:GetService("TweenService")

Gui.Position = UDim2.new(0.25, 0,-1, 0)

Part.Touched:Connect(function(hit)
	local Hit = hit.Parent:FindFirstChild("Humanoid")
	if Hit then
		local player = game.Players:GetPlayerFromCharacter(hit.Parent)
		if player then
			if player.OtherInfo.Backpack.Value < player.OtherInfo.MaxBackpack.Value then
				Gui:TweenPosition(
					UDim2.new(0.25, 0,0.01, 0),
					"In",
					"Sine",
					1,
					false
				)
			end
		end
	end
end)

I have this code to pop up a gui window when a player steps on a part but it the explorer it's tweening the gui but when you play the game nothing happens. Any ideas?

You have to tween the gui in the player.PlayerGui not starter Gui