Happy modding, and may your bootloader always be responsive!
What Is Android Fastboot Mode and How Does It Work? - miniOrange How to Open Fastboot Mode on OPPO Reno
To summarize the most effective path:
Are you planning to or are you trying to recover a device that is currently stuck? OPPO A5x – How to Enter Fastboot Mode Happy modding, and may your bootloader always be responsive
Note: If you try this on a locked bootloader, the phone will simply restart normally. the phone will simply restart normally.