I have an issue with exchanging code for the token when I try to log in with Facebook using their API not the SDK, I get the code just fine but when I make an API call with that code to get a token I get this error message "Error validating verification code. Please make sure your redirect_uri is identical to the one you used in the OAuth dialog request", the redirect uri i use in xcode is ("fb" + the appId + "://authorize", and that's working for getting the code but how do I add that in the Valid OAuth Redirect URIs inside the Facebook app settings?