Hey, Today i was trying to make an jetpack script. But why it isn't working?

local Players = game:GetService("Players")
local UserInputService = game:GetService("UserInputService")

local Player = Players.LocalPlayer
local JetpackGui = Player:FindFirstChild("PlayerGui"):WaitForChild("JetpackGui")
local JetpackFrame = JetpackGui:WaitForChild("JetpackFrame")
local Kalan = JetpackFrame:WaitForChild("Kalan")

local Yakit = Player:FindFirstChild("Configs"):WaitForChild("Yakit")
function key(inputObject, GPE)
	if not GPE then
		if inputObject.KeyCode == Enum.KeyCode.F then
			JetpackFrame.Visible = true
			
			if Yakit.Value >1 then
				game:GetService("ServerStorage"):WaitForChild("BodyVelocity"):Clone().Parent = Player.Character:WaitForChild("Head")
				
				local BodyVelocity = Player.Character:WaitForChild("Head"):WaitForChild("BodyVelocity")
				BodyVelocity.MaxForce = BodyVelocity.MaxForce +Vector3.new(0, 4000, 0)
				
				Kalan.Text = Player:FindFirstChild("Configs"):WaitForChild("Yakit").Value -1
				wait(.3)
				return 15
			else
				Player.Character:WaitForChild("Head"):WaitForChild("BodyVelocity"):Destroy()
				repeat
					Yakit.Value = Yakit.Value +1
					Kalan.Text = Yakit.Value
					wait(.3)
				until Yakit.Value >9 or Yakit.Value == 10
			end
		end
	end
end
UserInputService.InputBegan:Connect(key)

There aren't errors on OUTPUT!

Anonymous