To install a .zip update file, you generally use the "Local Update" method:

Because the X96 Mini is produced by various manufacturers using the same generic branding, there is no single "official" website. You can find this specific firmware file on reputable TV box community sites:

: Click "Update" and the box will reboot into recovery to flash the firmware.

The specific firmware package is a stock firmware update for the X96 Mini TV Box equipped with the Amlogic S905W processor. This update is typically used to fix bugs or reinstall the factory Android system. Where to Download

: While the link points to an older version, they frequently update their firmware repositories for the S905W chipset.