If we want to add an app and its notifications or notification categories in addition to the numerous settings for exceptions in Do not disturb mode, we simply navigate to the notification settings of the desired application.

If "Override Do Not Disturb" is enabled on the app settings, all notifications will be received or allowed on the OnePlus smartphone.

Android 10 | OxygenOS 10.0
Step 1:  Open the  Settings
Step 2:  Tap on  Apps & notifications
Step 3:  Tap on  See al apps
Step 4:  Choose an  app
Step 5:  Tap on  Notifications
Step 6:  Choose a  category
Step 7:  Tap on  Advanced
Step 8:  Enable or disable  Override Do not Disturb
  1. Open the Settings
  2. Tap on Apps & notifications
  3. Tap on See al apps
  4. Choose an app
  5. Tap on Notifications
  6. Choose a category
  7. Tap on Advanced
  8. Enable or disable Override Do not Disturb

OnePlus Instructions