Here are some popular Huawei unlock code calculator tools that support 16-digit codes:
Beware of "free" websites that ask you to download suspicious .exe files or complete "human verification" surveys. These are often malware. huawei unlock code calculator 16 digit
The process was deceptively simple:
Open-source projects like Huawei_modem_calculator_v2 and huawei_code_calculator provide scripts for calculating codes for older modems and routers. Here are some popular Huawei unlock code calculator