VIETNAM TECHNICAL VIEW
For advanced users, the only legitimate way to get a on the OPPO F3 is by installing a Custom ROM . The most stable and well-known option is LineageOS 15.1 (based on Android 8.1 Oreo), ported by independent developers on XDA Forums.
If you are a tech-savvy user who doesn’t mind a factory reset, go for it. If you use the F3 as a daily driver with critical data, stay on the current stable ROM.