Delete admin user after removing config.php

I have deleted config.php in NextCloud 16.04. When I try to create admin user using wizard it fails with message that admin username already exists.

I can create admin2 user and then i have two admin accounts. Is it possible to delete an account?

the user exists in the database. not in the config.php.

you have to delete the user in the database. there is a occ command for this.

Why would you delete the config.php? I guess NC cannot work without it.