How to test Facebook Authentication
That brings us to the point, how to test such integration fast and easy, well you can always add your local URL to the app settings page and that will allow you to access the app and test it.
You need to open:
https://developers.facebook.com/apps/{your-app-id}/fb-login/settings/?business_id={your-business-id}Navigate to Facebook Login through the menu on the left and the URL of your choosing:

And you are good to go…but there is even a easier way of doing it, by default the localhost is enabled so even if you did not add any URL you’ll still be able to access your app from it, and that is huge, if you are using Herd or Docker setup you definitely have the localhost set up for you and even you don’t it can be done quite easily.
For example other platforms such as Google & Apple do not support such functionality, adding new such link for an app in Apple...it's a journey...let me tell that much.
Having such option out-of-the-box is an advantage, saves you time and you can focus on other areas of the development.
The first time I’ve did such integration I didn’t knew about it and I was struggling to understand what URL to put and where.
Conclusion
Testing such implementation can be a hassle but there is always a better way of doing it. More about how to do the implementation can be read in my other article.