I need to reset my Apple ID password and it gives me the option of using my iMac as a place where I can reset it. After it says, "
Notification sent to unlock Apple ID.
You can now unlock your account from your Mac.
A message with instructions has been sent to *****(Mac)."
nothing happens. What does this mean?
Check and see if there are any notifications in the Notification Center on your Mac: Mac Basics: Notifications keep you informed - Apple Support
Notification Center
With Notification Center, you can see all of your notifications at a glance. To open Notification Center, click its icon 
in the menu bar, or swipe left with two fingers from the right edge of your trackpad.
You can reset your password when you go to your Apple ID account page and click Forgot Apple ID or password.
iMac Notifications
