Please read CAREFULLY my previous post in this thread. And also please read and follow CAREFULLY what is written in the link I posted.
2) Press and HOLD Volume+ button, then, witohut releasing such button, press and HOLD the Power button until the Blackview logo appears. As soon as the Blackview logo appears, STOP HOLDING the Power button but KEEP HOLDING the Volume+ button until the wrecked android robot with the "No command" text appears.
3) Now press and HOLD Power button, then, without releasing such button, press ONLY ONCE the Volume+ button. Now release the Power button.