Requesting permission to send out subscription messages
Due to the latest released version of Messenger Platform, all page owners in Facebook now need to request permission to enable their Facebook pages to send messenger campaigns to their subscribers.
2. Click Messenger Platform.
3. Scroll down to the Advanced Messaging Features.
4. Click Request beside Subscription Messaging.
5. Select News in the Request Subscription Messaging window.
6. Give a short description of the kind of messages you will send in the box provided.
7. Provide examples of messages in the fields provided.
8. Check the box to confirm and agree to the policies and then click Save Draft.
9. Click Submit For Review.
There will be a confirmation pop-up that your request has been received.
Once approved, the Subscription messaging section under Advanced Messaging Features will have a green check mark on it.