I'm building an integration that manages Instagram Messenger chats on behalf of clients. In the past I've done an integration for Facebook Messenger.
I'm stuck on how to actually get the client Instagram subscribed to our Instagram Messaging webhook events.
The 'Setup webhooks' section on the Instagram Messaging docs just points to the general webhook setup for the messenger platform, which explains to use the /PAGE-ID/subscribed_apps endpoint specifying the fields (events) to subscribe to. I do this with the previous Facebook Messenger integration, but with Instagram I'm running into several problems.
First I tried to subscribe to the following fields messages, message_reactions, messaging_seen
An error response explains it's not possible to subscribe to messaging_seen.
Then I try with only messages, message_reactions and get the error pages_messaging permission is required which is not mentioned in the Instagram Messaging docs.
I'm only aware of these issues because I'm failing the App Review because the webhooks are not working for the reviewers. In testing my own Facebook Page / Instagram Business account it is working fine presumably because I own the Page/IG account I'm trying to connect. Because of that I've been able to record a complete video of the functionality, but the reviewer feedback keeps implying that they also need recreate that functionality themselves to pass it.
This thread suggests to use mocking, but I think that's for the creating the video rather than for the reviewers to use. I'm also not sure how you would mock something like the delete function without the webhooks anyway.
I haven't been able to find much information about this, so any pointers would be greatly appreciated