: Sites like HardReset.info maintain databases of stock firmware if you need to flash or restore your device to its original state.
If you have downloaded a specific firmware zip file, you can install it manually: Move the downloaded firmware file to the root directory of your SD card. Turn off your phone. Press and hold the Volume Down buttons simultaneously to enter Recovery Mode Select your language and choose Install from storage device
Do NOT use random oppo f3 update 80 download link from file-hosting sites (Mediafire, Google Drive, etc.). Unofficial packages may contain spyware or cause a permanent hard brick.
