Forgot password to old Mac
Bought a new iMac. So I wiped out my old iMac 27" and put a new system on it months ago. I forgot the password. Holding Command r only brings up a black screen with a pad lock. When I am on my new Mac under system settings Apple account, I can see my new Mac and old Mac. What do I do to be able to reset my old Mac's password? Thanks
iMac 27″, macOS 12.7