The developer options offer settings that are useful for developing apps and software, but also provide some functions that are needed for example for synchronizing data.

The developer options can be activated on the Oppo-Smartphone by tapping 7 times on the build number. Only then the menu item for the developer options is visible.

Different from what you are used to under Android, the developer options can be found again after activation under the menu item "Additional settings".

Android 10 (ColorOS 7.0)
Step 1:  Open the  Settings
Step 2:  Tap on  About phone
Step 3:  Tap on  Version
Step 4:  Tap  Build number  seven times in a row
Step 5:  Enter your  PIN/Password/Pattern
  1. Open the Settings
  2. Tap on About phone
  3. Tap on Version
  4. Tap Build number seven times in a row
  5. Enter your PIN/Password/Pattern

Oppo Instructions