How to programmatically subscribe messenger webhook

Question

I was trying to implement Facebook Checkbox for my customers but I realized that it's required to subscribe to the messenging_optins event to render Facebook checkbox. So I tried to subscribe to the messaging_optins event programmatically.

Note that my facebook app is in development app. So in fact, I still test on my Facebook account.

curl -i -X POST "https://graph.facebook.com/v3.2/{my-customer-page-id}/subscriptions?access_token={my_app_access_token}&callback_url=https%3A%2F%2Fmy-server.ngrok.io%2Fwebhook%2Ffacebook&fields=messaging_optins&object=page&verify_token=abc123abc123456"

The response is {"success":true}

But my Facebook Checkbox still does not work until manually go to Facebook Developer setting and subscribe to the Page as the below screenshot.

I realize that the above curl command just help me subscribe to the Page Webhook (not Messenger webhook) event as the below screenshot.

Can anyone point me out why I can't subscribe to "Messenger event" but Facebook graph API return that it successfully subscribed?

Thanks.

Answer 1

After 1 day digging Facebook Docs, try and test many cases with Facebook Graph Explorer, I finally found the way to programmatically subscribe to the Page's Webhook.

In Facebook Docs, it had writes 3 lines like this

Webhooks for Messenger allows you to receive real-time notifications when a variety of interactions or events happen, including when a person sends a message. Webhooks for Messenger works a little differently than other Webhooks so please use the Webhooks for Messenger docs when setting up this type of Webhook.

Here is the way I subscribe messages, messaging_postbacks, messaging_optins, message_reads events. Refer to: https://developers.facebook.com/docs/graph-api/webhooks/getting-started/webhooks-for-pages

curl -i -X POST "https://graph.facebook.com/v3.2/{page-id}/subscribed_apps?access_token={page-access-token}&subscribed_fields=messages,messaging_postbacks,messaging_optins,message_reads"