: In the "Advanced" category of the Button Mapper (pro) app, you can input a reboot recovery shell command. When you trigger the mapped button, the app executes this command to reboot the device directly into recovery mode without needing root permissions.
: This is the most reliable "no root" way to reboot into recovery. You must connect your phone to a computer and use the command adb reboot recovery . recovery reboot apk no root exclusive