Modern Mi Unlock tools (versions 7.x and 8.x) come with strict server-side policies. The most notorious is the mandatory for new accounts or devices. For power users who flash multiple ROMs a week, this is a productivity killer.
The tool should now show "Phone connected." Click . You will likely see a warning that unlocking is dangerous; click Unlock Anyway . mi unlock 6.5.406
You have a newer HyperOS device (Android 13/14). For HyperOS, you generally need MI Unlock 7.x or the newer HyperOS Unlock Tool . Version 6.5.406 will likely throw a "Device not supported" error on the Xiaomi 13 or 14 series. Modern Mi Unlock tools (versions 7