Go back to > System (or Additional Settings) > Developer Options . Enable OEM Unlocking and USB Debugging . Phase 2: Link Your Mi Account
Open the Mi Unlock Tool and sign in with the used on your phone. Once the tool detects your device, click Unlock . black shark 2 unlock bootloader
Tip: Do not log out of your Mi account or factory reset your phone during this time, or the timer might reset. Go back to > System (or Additional Settings)