Historically, Huawei modems and routers were locked via a firmware algorithm. When a user inserts a non-accepted SIM card, the device prompts for an "Unlock Code." If the user inputs the correct code, the restriction is lifted forever.
You can find various versions of this calculator across these platforms: Huawei Unlock Code Calculator V3 Download
app on Google Play specifically mentions support for v1, v2, and v3 codes for modems. Paid Alternatives : Services like DC-Unlocker Historically, Huawei modems and routers were locked via