I am unable to add "notifications" to the "Realtime Update Subscriptions" of my app in Facebook. In the "Realtime Updates API" page of the Apps Settings in developers.facebook.com, I have the following settings:
Object: user
Fields: notifications
Callback: http://myserver/callback
Verify token: my_token
if the Fields is set to "feed", it works, but if I attempt to save with Fields set to "notifications", it failed with the following error:
Error Couldn't save 'user': Application cannot subscribe to notifications
Is there anything I need to configure? I have tried adding all "Permissions" under "Permissions" page.
Any input will be highly appreciated! Thanks in advance!