Apple iPad Pro 12.9 (2018)
iPadOS 16.1
1. Find "Display & Brightness"
Press Settings.
Press Display & Brightness.
2. Adjust screen brightness
Press and drag the indicator below "BRIGHTNESS" right or left to select the required brightness level.
3. Turn automatic brightness on or off
Press Accessibility.
Press Display & Text Size.
Press the indicator next to "Auto-Brightness" to turn automatic brightness on or off.
4. Return to the home screen
Slide your finger upwards starting from the bottom of the screen to return to the home screen.