Webflow Webhooks Authentication issue

Note: This is for using a webhook with a no-code solution.

I’m creating a Trigger to update multi-reference fields in a webflow CMS collection so it matches a collection in Airtable. Since there is no way to multi-reference fields normally, I am using the Webhook by Zapier app to make this happen. I have followed this tutorial exactly, but when it comes to the Auth step (around the 8:50 mark of the tutorial), I am getting a 400 error in Zapier (and a 422 in my browser console). 

Zapier support suggested moving my Auth to the `Basic Auth` form field, however since this is an API token from Webflow, I believe that it should be set up as it’s own header, as I have done. 

I’m not getting any other errors, and all previous steps have passed testing and provided the correct information, so I am uncertain about what is failing. I’ve triple checked that all of the fields match was has been done in this tutorial (the only difference is that mine is for New and Updated record and the tutorial just uses New), and I’ve validated that all of the naming and references are consistent between Airtable<>Zapier<>Webflow. I have also read through every support doc on webhooks and forum question with no luck of this auth step passing (have also checked to ensure that the token in Webflow is still active in addition to creating a new one to ensure that I didn’t have a typo in a previous version). 

I am wondering if since that tutorial is from a year ago if something around auth may have changed for Zapier? I’ve included screenshots of what I have set my trigger to and the error that I am receiving. Any suggestions would be super helpful!