Connect PHP login with Laravel APP with its own login

I have done a software using Laravel 5.4 and it has a login system. This software is a submodule for another app developed with PHP with its own login system.

What I want to do is to, somehow, bypass my Laravel app to automatically login once the user has logged in the main PHP app. Using the same MySQL database, of course.

Maybe that's a bad idea and I should ¿delete? my Laravel login. I am missing ideas.

How is the best/easy way to do this? Any tip?

Thank you in advance.

via Chebli Mohamed