My understanding is that you cannot unlock China devices currently
https://xiaomi.eu/community/threads/known-unofficial-unlock-xiaomi14-and-k70-series-bootloader-methods.70843/post-744411
@Xander00 For newer ROMs, you would need an account based in China to unlock a Chinese device.
As far as I understand, even non official services cannot unlock Chinese devices currently.
It is regularly updated when it no longer work, check that you have the latest one.
https://xiaomi.eu/community/threads/xiaomieu-module-app.70890/#post-743527
@novakt The module won't work on this ROM
I think you would need to root, and use this : https://xiaomi.eu/community/threads/installing-magisk-and-play-integrity-fix.70553/