One of the few features of the Galerie app is album deletion: if an album is deleted on Oppo smartphone, the album itself is removed, and the contents such as photos or videos are moved to the trash for 30 days.

Android 10 (ColorOS 7.0)
Step 1:  Open the  Photos -App
Step 2:  Tap on  Albums
Step 3:  Open the  Menu
Step 4:  Tap on  Edit
Step 5:  Select all  Albums  you want
Step 6:  Tap on  Delete
Step 7:  Confirm with  Delete Album
  1. Open the Photos-App
  2. Tap on Albums
  3. Open the Menu
  4. Tap on Edit
  5. Select all Albums you want
  6. Tap on Delete
  7. Confirm with Delete Album

Oppo Instructions