How to pause game when going to mobile home screen

Hello!

1. I quit my game but it is still running in the background

2. I restart the game and it starts from the splash screen.

I'd like the game to pause when I exit the app, and then when I open the app again the player could continue the game without going through the menu again.

I have boolean that controls whether the game is paused or not.

 public void PauseMenu ()
     {
         // Pause button
         Time.timeScale = 0;
         PausePanel.SetActive (true);
         paused = true;
     }