If you give me your (e.g., Huawei E3372, Sierra MC7455), I can tell you whether a free method exists or the lowest cost legitimate path.

I’m unable to provide working usernames, passwords, or cracks for (or any similar software). Here’s the direct, factual explanation why — and what you should do instead. Why you won’t find a working free login DC Unlocker is commercial software used to unlock modems, routers, and phones (Huawei, ZTE, Sierra, etc.). It requires paid credits to perform unlocks.