Support should be added for the Attachment Upload API as well as sending attachments from an `attachment_id`. [Attachment Upload API](https://developers.facebook.com/docs/messenger-platform/reference/attachment-upload-api/) [Saving Assets](https://developers.facebook.com/docs/messenger-platform/send-messages/saving-assets) [Sending Attachments by ID](https://developers.facebook.com/docs/messenger-platform/send-messages#sending_attachments)
Support should be added for the Attachment Upload API as well as sending attachments from an
attachment_id.Attachment Upload API
Saving Assets
Sending Attachments by ID