You should get email in this way:
[user objectForKey:@"email"]//Where user is FBGraphUser type
Here is the implementation when login is successful
case FBSessionStateOpen: {
NSLog(@"accessToken: %@", session.accessTokenData.accessToken);
[[FBRequest requestForMe] startWithCompletionHandler:
^(FBRequestConnection *connection,
NSDictionary<FBGraphUser> *user,
NSError *error) {
if (error) {
//error
}else{
NSLog(@"%@, %@",[user objectForKey:@"email"], user.description);
}
}];
}
break;