To use secret codes on your OPPO A9 2020 Go to product viewer dialog for this item.
Secret codes, also known as dialer codes or engineering codes, are special codes that allow you to access hidden settings and features on your smartphone. These codes are usually entered into the dialer app, and they can provide you with valuable information about your device, as well as allow you to tweak advanced settings.
: Accesses a hidden page showing saved calendar events and related data.
: Used on some updated models as a shortcut to bypass setup screens (use with caution). Important Usage Tips