For modern Huawei devices, the unlock algorithms are complex. The safest way is to pay a professional unlocking service (often found on eBay or dedicated unlocking sites like dc-unlocker).
To unlock it, you generally need two things: huawei+modem+unlocker+v577+work
Reading or resetting the internal lock counter and applying an unlock code. IMEI Writing: For modern Huawei devices, the unlock algorithms are complex