If the website doesn’t show the firmware, Oppo regional sites sometimes remove old builds. Contact Oppo support directly or visit a service center for official flash files.
Your only option is an unofficial custom ROM (e.g., LineageOS 14.1). This requires: oppo f3 nougat 711 official update download top
Not recommended unless you are an advanced user. If the website doesn’t show the firmware, Oppo
No, if you use the official OTA/local update. But a backup is always recommended. Your only option is an unofficial custom ROM (e