OPPO does not want casual users in Fastboot. If you are a developer or enthusiast, apply for the Deep Test unlock. If you are just trying to fix a frozen phone, you do not need Fastboot – use Recovery Mode instead (Power + Volume Down).
Entering Fastboot Mode is generally safe, but it involves low-level system access. To ensure your device remains unharmed, prepare the following: How to Open Fastboot Mode on OPPO A5 2020
Because OPPO requires you to first. On the OPPO A5 2020, even in Fastboot mode, the command fastboot flashing unlock will fail with a "remote: Permission denied" error unless you have completed the Deep Test APK approval process. OPPO does not want casual users in Fastboot
: Once the device is off, press and hold the Power Button and Volume Up button simultaneously. Entering Fastboot Mode is generally safe, but it