The unlocker needs your modem’s IMEI (15-digit number). You can find it:

Consulting the (e.g., E3372, E3531) usually found on the device sticker or under the battery cover is the first step in identifying the correct support resources. Unlock Huawei Modems - 3Community - Three Ireland

: Generates 8-digit unlock codes (NCK) using the device’s unique serial number.

Plug your Huawei modem into your PC's USB port (without a SIM card or with an "unsupported" one).

if it came in a ZIP or RAR archive (use 7-Zip or WinRAR).