The albums or collections created in the Gallery app of the OnePlus smartphone can be deleted at any time.

Deleting an album will also delete all stored files in the album.

Android 10 | OxygenOS 10.0
Step 1:  Open the  Gallery app
Step 2:  Tap on  Collections
Step 3:  Tap and hold an  album/collection
Step 4:  Tap on  Delete
Step 5:  Confirm with  Delete
  1. Open the Gallery app
  2. Tap on Collections
  3. Tap and hold an album/collection
  4. Tap on Delete
  5. Confirm with Delete

OnePlus Instructions