How to authenticate user from the respons of rest API?

Hi there, I am creating a laravel application using two laravel applications. The first laravel application will be used for handling API requests, the second one will be used for making a request to the first laravel application. The second application will also have a login form. On the submit of the login form, I am sending the form data to the first application which in return gives back the user data. Now what I want is to log the user into the second application without using its own database(second application database).