If your device is hard-locked or the IMEI method is unavailable, software tools can modify the internal firmware. MF920U Quick Start Guide - FCC Report
The ZTE MF920U unlock firmware is a custom firmware that allows users to unlock their device from the default carrier restrictions. This firmware is designed to replace the original firmware, providing users with advanced features, improved performance, and most importantly, the ability to use their device with any compatible network. Zte Mf920u Unlock Firmware