Some ZTE subsidiaries offer direct downloads:
The ZTE MU5001 is one of the most powerful portable 5G routers on the market, offering blazing-fast speeds and reliable connectivity. But like any sophisticated device, its performance depends heavily on keeping its firmware up to date. Zte Mu5001 Firmware Download
If you're unable to find the firmware on the ZTE official website, you can try alternative sources: Some ZTE subsidiaries offer direct downloads: The ZTE
ZTE does not host a public “downloads” page for consumers like some brands. Instead, you must use one of these three legitimate channels: Zte Mu5001 Firmware Download