If the user clicks “Accept” in the request, he will be sent to the URL of the canvas page of the application that sent the request with request_ids
https://apps.facebook.com/[app_name 022/? Request_ids = [request_ids]
Make your own URL 1) store request_id in your application using a special link 2) when the user accepts the link, reads request_id and launches the custom URL
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