How to make custom auth query in Laravel

I'm new using Laravel, I have some problems, when I create auth using command

php artisan make:auth

It's automatically create Auth controller and views and default user table, here I wanna make some different auth, I have a table like this

employees

id | reg_number | name

users

id | name | password | remember_token | employee_id | created_at | updated_at

and when I login I want to join employees and users so the query be like

select users.*, employees.reg_number inner join employees on employees.id = users.employee_id

then I want login using reg_number and password

how to create like that?

I've been searching on many sites, but have no answers thanks for answer and sorry for bad English, :)

via yulianto saparudin