Since the official free method is defunct, third-party services like are the most direct remaining software-only options.
Since official channels are closed, you must use a paid third-party service to "read" or "calculate" your device's unique unlock code. Paid Software Tools: Services like DC-Unlocker Ministry of Solutions How to Unlock Bootloader in HUAWEI Honor 8C phone
Requirements
Troubleshooting
(XDA Developers, 4PDA)