That's odd - we're using the save2 endpoint for collecting third-party form data and aren't using formVid (just formid). All data comes over fine.
Comes and goes (like that other thing we've been discussing).
That Embedded Data area is kind of strange -- if there's an effort to process the webhook response it should also cover the success object, not just the error object. Are you sure you need that?
"embedded data" is qualtrics terminology for custom fields... On the left are the field names and on the right the json names from which the field values will be extracted.
These variables are not mandatory but interesting in debug mode
None in this case. It's all back-end so it has no relevance if you're not GETing a follow-up page.
The (perhaps far-fetched) use for the followUpUrl would be that you could use form logic to return different vars to Qualtrics.