authenticate user

I am the sole user and administrator. I have repeatedly tried to use my user password--I used it to log into my MacBook to start this session and had to use it to access this forum so I know it works--but it will not unlock my MacBook to install the latest update. Any further suggestions?

This normally requires an administrator password (not Apple ID). If you are the sole user and administrator, this will be your login password (not Apple ID)