What to do if advanced administrator settings on mac were incorrectly changed?

Question

macOS

Good afternoon!
There was a problem, incorrect data was entered in the advanced account settings. They were saved and the computer was restarted, that is, they took effect.
And now it is possible to enter the system itself, the password works. But it doesn't allow changes. Clicking on the Lock icon opens the dialog box as before, but without the preselected Username. When entering the current user and password from the account, it shows an incorrect data bundle.
What can be done in this situation? I'm not afraid to lose data, the computer is clean. The main thing is to return the opportunity to make changes.
So far I have found only similar tips (did not have time to use, the computer is not at hand) https://mac03.ru/2013/01/13/repair_lost_admin/, but perhaps they are initially off topic.
Thanks in advance!

Answer 1

here infa how to create an admin account and give admin rights to the desired user
https://support.apple.com/en-us/HT203538
https://apple.stackexchange.com/questions/323495/r...