faab TI uses Laravel Auth in the background. You would need to know the password.
Auth::authenticate([
‘email’ => ‘you@you.com’,
‘password’ => ‘password’,
], TRUE, TRUE);
Edit: It seems there are other Laravel ways too, without needing the password:
https://laravel.com/docs/7.x/authentication#other-authentication-methods
Bear in mind in TI that a user is an instance of Customers_model