How do you add a fb registration? ipb 4.2.2

I'm new to the fb side of adding fb login scripts to my ipb forums and want to know what i'd need to do exactly to get the Facebook Login working properly so people can register using facebook instead of happening to sign-up.

I'm at the point where, I have to enter a scripting code to my forums, but unsure where to add the script, to what page to get it working. I enabled the facebook app with the right appid and secret id code just unsure what to do next.
Could anyone help me please? Thank you!

I have IPB 4.2.2 Community Suite

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Does anybody know the answer too this? I'm still having a issue with setting this up.