# Webinar Promotional Source Links for API Integration **URL:** \ **Category:** Webinars\ **Tags:** webinar\ **Created:** [August 11, 2022, 12:45pm UTC](https://devforum.zoom.us/t/webinar-promotional-source-links-for-api-integration/74060 "2022-08-11T12:45:15Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![community3](https://avatars.discourse-cdn.com/v4/letter/c/ecae2f/32.png) [@community3](https://devforum.zoom.us/u/community3)\ **Post date:** [August 11, 2022, 12:45pm UTC](https://devforum.zoom.us/t/webinar-promotional-source-links-for-api-integration/74060/1 "2022-08-11T12:45:15Z")
We are using the registration webhook and would like to pull in fields for promotional source links. Is this part of the data payload sent in the webhook? For example, a user registers for a webinar through a custom source link provided in the platform labeled “Facebook” ([https://XXX.zoom.us/webinar/register/XXXXXXXXXXXXX/WN\_t6bik3raSH2bpfNzdgznkw](https://XXX.zoom.us/webinar/register/XXXXXXXXXXXXX/WN_t6bik3raSH2bpfNzdgznkw)). How can we identify using the webhook that this registrant came from our “Facebook” source link? Thank you in advance! Marie ---
**Author:** ![rehema.zoom](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/rehema.zoom/32/40323_2.png) [@rehema.zoom](https://devforum.zoom.us/u/rehema.zoom)\ **Post date:** [August 11, 2022, 2:41pm UTC](https://devforum.zoom.us/t/webinar-promotional-source-links-for-api-integration/74060/2 "2022-08-11T14:41:11Z")
Hi @community3, Thanks for your question. When you make a request to add a registrant, the API responds with a registrant\_id for each one. This is also sent in the webhook event and can be matched by requesting all meeting registrants with this API: [Zoom Meeting API](https://marketplace.zoom.us/docs/api-reference/zoom-api/methods/#operation/webinarRegistrants) Thanks, Rehema