I created an application for a website and gave it a site url. (The site url is actually not real. It is overridden in my local hostname file for development purposes. Does this matter?).
I used the sample code for creating a request dialog to send requests to another facebook account. I used the multi-user interface, without the to: field. When I refresh the page in my other facebook account, I see a red 1 on the world icon for just a split second, but then it disappears and there is no notification to be found. It does this every time I send a request. Is there something wrong with my requests that they are getting deleted instantly? Have I configured my app wrong in some way?
I have had the exact same problem, I was able to fix this by entering a url in the Website part of https://developers.facebook.com/apps apps basic information, add an app domain and a canvas url ... i suspect it will work with only the canvas url since this is the url where the notification links to.
hope it helps,
cheers!
来源：https://stackoverflow.com/questions/8677823/notification-for-facebook-app-requests-not-showing-up