Use or third-party tools like Miracle Box / Octoplus (paid) for QCN.
Disclaimer: This guide is for educational purposes. The author is not responsible for data loss, IMEI null errors, or hardware damage. Always use official firmware sources when possible. Oppo A9 2020 Firmware
Yes – use the “System Update” option in settings with a local OZIP file, but only if the phone still functions. Oppo A9 2020 Firmware — Quick Guide Oppo’s