Sites like https://streeteasy.com/ and https://www.geeksforgeeks.org/ incorporate the same UI that allows you to log-in using Google Auth with one click. The photo below shows an example.
Since many sites have this identical UI, I assume there is some Google/Firebase mode, but I do not see documentation related to this.
Perhaps this link in the html provides some help in figuring this out? ux_mode=popup I am familiar with, but ui_mode=card I am not. https://accounts.google.com/gsi/iframe/select?client_id=388036620207-3uolk1hv6ta7p3r9l6s3bobifh086qe1.apps.googleusercontent.com&ux_mode=popup&ui_mode=card&as=al2HYo2TiehJpHITNY8fJQ&channel_id=9384f02a26b236ce29c0acab5000e8c656b9bbfb3202c094cd65f92e2468d6a3&origin=https%3A%2F%2Fwww.geeksforgeeks.org
