You want to install the latest official OTA (Over-The-Air) update provided by ZTE.
Use a working computer and a stable USB cable. 2. Download ZTE Blade L220 Firmware (Stock ROM) Firmware ZTE Blade L220
Improves the responsiveness of the UI. Security Updates: Protects against vulnerabilities. You want to install the latest official OTA
Reinstalls the operating system if the phone won't boot (boot loop). Why Update or Reinstall Firmware? Firmware ZTE Blade L220
Ensure the firmware version is exactly for the L220. Using firmware from a different region or model can cause errors.