You should never leave your device unlocked when you walk away from it. However, we all make mistakes. You can alter the amount of time it takes for your device to lock on its own to add an extra layer of protection. Shorten the timer to as short as you are comfortable — less than one minute is ideal. To do this on your iOS device:
- Go to Settings.
- Go to Display and Brightness.
- Go to Auto-lock.
- Select how long you want your device’s screen to stay on.