Authentication of Google Extension via Google/laravel spark

please excuse my ignorance here! Can someone point me in the right direction to a tutorial or walk through that shows how to create a login via email password on an external application (in my case a google extension) that authenticates the user via laravel. I would also like the option to authenticate users using Google. I know the sort of theory just looking for a sample/tutorial (socialite is an option if i can get it to work with laravel spark!)

The authentication i mean is for an external application - so just authenticating with laravel spark (is subscription valid) then the generating a token (the bit i need a tutorial on) in order to remain logged in to the chrome extension Thanks for any pointers!