Im trying to send an app request through facebook using the facebook iOS SDK, im using the following code:
NSString *message = [[NSString alloc] initWithFormat:@
andyc,using that way you can only send the App request. And please make sure you have registered you App as "App On Facbook". The problem is that in order to have the notification displayed on the desktop website, your Facebook App needs to have a Canvas URL defined. The URL doesn't even need to be valid, it just needs to be defined in the Settings of the App. I have verified with a test app that this does indeed resolve the problem. This is done intentionally by Facebook because when the user clicks on the notification, they are sent to your Canvas URL on the desktop website
I have done things in same way and i am getting the App request in my Notifications. still you have problem with sending app request then please view below link
"apprequests" dialog reports success, recipients receive nothing