I'm hoping someone can provide guidance about user authentication in Angular. I want to use an authentication service that offers an SDK to handle user authentication (registration, login and logout). Preferably, the authentication service should offer authentication through social platforms like Google or Facebook.
I have looked into Okta's auth0 but it is not free and open source (although I know it does have a free plan). What is the best alternative (specifically for Angular) to Okta's auth0 that is free and open source? I am using PHP for my backend.