Have you ever wondered how third-party login systems like "Login with RingCentral," "Login with Google," or "Login with GitHub" work in modern web apps? All of these login flows work by integrating third-party OAuth 2.0 logins, generally with the host app's own login system.
In this article, let's learn the fundamentals of OAuth 2.0 Authorization Code Flow and then implement the same in an example Node.js/HTML5 web app (available on GitHub) that provides "Login with RingCentral" functionality for users to login using their RingCentral account.