Method 1:

1. Turn on the phone, click "Settings" and select "General".

2. Click Software Update and select Download and Install to turn on automatic update.

Method 2:

1. Click to enter the "App Store" and click on the personal avatar.

2. In the available updates, click Update All to return to the home screen and open Settings.

3. Click "iTunes store and App Store", and in the automatic download, just open the button on the right side of "Application Update".