After downloading the official firmware package below meant for ZTE Blade Apex, follow flashing instructions at post end to learn how to install the ROM. An SDcard is required for this process.
Always post in comments section if you find any broken link.
ZTE Blade Apex – Download
How to flash
Follow flashing instructions provided via this link https://www.leakite.com/2016/09/how-to-flash-zte-stock-rom-firmware-via.html