how to get fb page scoped user id for sending message

Question

I want send message as shown link https://developers.facebook.com/docs/messenger-platform/send-api-reference#rate_limit You can see parameter "USER_ID". How to get page scoped user id? please show screenshot and provide detailed answer.

Answer 1

Currently, there is no official method to connect user_id and page_scoped_id in both ways. You can hack it by picture_url because both URLs are same. see https://chatbotsmagazine.com/fb-messenger-bot-how-to-identify-a-user-via-page-app-scoped-user-ids-f95b807b7e46#.kcae9367y