Unlocking a locked macOS with iPad
Black lock on y Mac.
tried unlocking with various keys. Can I use my iPad to unlock?
[Re-Titled by Moderator]
iMac 21.5″, macOS 10.15
To deal with a Firmware Locked Mac, see > Set a firmware password on your Mac - Apple Support
If this is a used Mac that you just purchased, then you need to contact the seller and have then unlock it or... you need to return it and get your money back.