ServerScriptService.Platform Detector:11: unexpected symbol near '?'???

my code:

game.Players.PlayerAdded:Connect(function()
         ismobile = game:GetService('UserInputService').TouchEnabled
         if ismobile == true then
            print('mobile') 
         end

      isonpc = game:GetService("UserInputService").KeyboardEnabled

      if isonpc == true  then
         print('Pc') 
      end

   isconsole = game:GetService('UserInputService').GamepadEnabled

   if isconsole == true then
      print('xbox')
   end
end)