NativeUI index value nil

Hello.

I have an issue with my script. The NativeUI menu isn’t recoginized by my car script hence the script isn’t loading

the code:

_menuPool = NativeUI.CreatePool()

mainMenu = NativeUI.CreateMenu(“Main Menu”, “~b~Menu test description”)

_menuPool:Add(mainMenu)

function FirstItem(menu)

local submenu = _menuPool:AddSubMenu(menu, "~b~Vehicle list") 

local carItem = NativeUI.CreateItem("Banshee")

local carItem = NativeUI.CreateItem("Adder")

local carItem = NativeUI.CreateItem("Buffalo")

end