officially received an update to Android 7.1.1 Nougat in early 2018, though the device originally launched with Android 6.0 Marshmallow. While official support has since ended, community-driven forums like XDA Developers
via custom firmware found on XDA requires a specific technical process that carries risks, including voiding your warranty or "bricking" the device. Opposite F3 Nougat Update Forum Xda
XDA Developers forums were active around the Oppo F3 Nougat update, highlighting several recurring themes: officially received an update to Android 7
For more specific help, please confirm your phone’s exact model number (found in Settings > About Phone). Opposite F3 Nougat Update Forum Xda