qfil.exe --port=\\.\COM3 --programmer=prog_emmc_firehose_9x07.mbn --flash=full_firmware.bin
If the official FOTA update is not an option, various regional versions and modified firmwares are often hosted on technical forums and file repositories: MF79U - ZTE - Support
The changelog for the ZTE MF79U firmware full may vary depending on the version. Here are some general changes that may be included:
Connect the dongle, install the drivers, and use a terminal program (PuTTY, CoolTerm) on the virtual COM port: