Fastboot Mode , you can use either a physical button combination or a computer-based ADB command. Method 1: Hardware Button Combination
How to Open Fastboot Mode on Oppo A37
If you get stuck or need to go back to the standard operating system after finishing your tasks: how to open fastboot mode on oppo a37 verified
Before entering Fastboot mode on your Oppo A37, make sure to: Fastboot Mode , you can use either a