Keep holding both buttons until the ZTE logo appears on the screen. When you see the logo, release only the Power button , but keep holding Volume Up .
Performing a hard reset will erase all personal data, including photos, music, and accounts, and restore the phone to its original factory state. How to Hard Reset ZTE Blade A34
Use this method if the screen is frozen, stuck on the ZTE logo, or you’ve forgotten your lock screen credentials. Keep holding both buttons until the ZTE logo