OPPO F3 never received an official Android 7.0 (Nougat) or higher update. Update 80 is the final maturity stage of the Android 6.0-based ColorOS.
Press and hold the and Volume Down buttons simultaneously to enter Recovery Mode . oppo f3 update 80 download link
There is for the OPPO F3. The device has reached its end-of-life for updates. Users seeking newer features or security should consider switching to a supported device or, if technically savvy, exploring verified custom ROMs from trusted XDA threads—never from unknown download portals. OPPO F3 never received an official Android 7