I wanted to update this Thread as I just installed Facebook Login on my forum today.
I'm going to keep this simple how I set it up.
Step #1
https://developers.facebook.com/
Step # 2 Add a New App
Step #3 Create a New App ID
Display Name - I use my domain here with mydomain
Contact Email - enter your email address
Step #4 Security Check
Fill out the captcha in the Text in the Box
Step #5 Make a new Text Doc, copy and paste the App ID and the App Secret you will need this later when you setup Facebook on your forum.
Step # 6 Thing to Fill out using the Settings Basic Tab
1.) App Domains
Don't use
http://www. or
https://www. or www.
Use name only - mydomain.com
I'm not sure if you need to use them but I filled them out.
Privacy Policy URL
Terms of Service URL
2.) + Add Platform
3.) Click on Website
4.) Paste in you Web Site URL
http://www.mydomain.com/community/index.php
Step #7 Settings Advanced Tab
I just left the default settings and didn't change anything.
Now setting up your Forum for Facebook,
Step #1 go to your Admin Control Panel
1.) Click on Options
2.) Click on Facebook Integration
3.) Enter your Facebook Application ID
4.) Enter your Facebook Application Secret
I left everything else on the default settings.
Now it time to test everything
1.) Now go to your Tool Tab
2.) Click on Test Facebook Integration
This will test the XenForo's Facebook integration. You must have a Facebook account to perform this test.
3.) Click the Run Test button.
If everything work fine, you should see Test Passed! with the following information.
Name associated with your Facebook account an your Email address associated with Facebook account along with your Facebook Profile image.
I hope this help someone on setting up XenForo's Facebook integration