How I can use backoffice credentials in the FrontOffice


I am a beginner in Pimcore. This is my problem: I would like to use the backoffice credentials (for my usecase they represent the admin’s credentials) to login in the front-office as well. By default it seems that pimcore provides the table “users” which contains the backoffice users. I want to be able to use these credentials in the FO as well. I’ve studied how the authentication is working on pimcore and my idea was to insert the “admin_provider” into the security.yml

The problem is that I don’t know where the entity class for the users table is declared. Can you please help me to understand how to find the users entity in order to add in the security.yml?

I hope I’ve been clear enough.
Thanks in advance for your help.