On the Oppo smartphone, the operating aids offer a magnification function that is similar to a magnifying glass. 3 quick taps on the screen open the zoom window, and with two fingers you can zoom in and out.

The magnification works on the whole screen, except the keyboard and navigation bar.

Android 10 | ColorOS 7.0
Step 1:  Open the  Settings
Step 2:  Tap on  Additional settings
Step 3:  Tap on  Accessibility
Step 4:  Tap on  Magnification
Step 5:  Enable or Disable  Magnification
  1. Open the Settings
  2. Tap on Additional settings
  3. Tap on Accessibility
  4. Tap on Magnification
  5. Enable or Disable Magnification

Oppo Instructions