To get quick access to a feature of the OnePlus smartphone's accessibility features, we can activate a volume button shortcut and select one of the following functions:

Once the function has been enabled and a shortcut has been selected, the desired operating aid can be started by pressing and holding the volume keys for 3 seconds.

Android 10 | OxygenOS 10.0
Step 1:  Open the  Settings
Step 2:  Tap on  System
Step 3:  Tap on  Accessibility
Step 4:  Tap on  Volume key shortcut
Step 5:  Enable or disable  Volume key shortcut
Step 6:  Tap on  Shortcut service
Step 7:  Choose a  Shortcut service
Step 8:  Tap on  Back
Step 9:  Enable or disable  Allow from lock screen
  1. Open the Settings
  2. Tap on System
  3. Tap on Accessibility
  4. Tap on Volume key shortcut
  5. Enable or disable Volume key shortcut
  6. Tap on Shortcut service
  7. Choose a Shortcut service
  8. Tap on Back
  9. Enable or disable Allow from lock screen

OnePlus Instructions