Not seeing "Sentry-Hook-*" headers for WebHook

I just created a WebHook integration (version 9.1.2).

I’ve been testing it and I don’t see any of the Sentry-Hook-* headers I would expect as documented:

The headers I see look like this:

   "accept-encoding":"gzip, deflate",
   "user-agent":"sentry/9.1.2 (",

Any idea why I’m not seeing said headers and how I can proceed to validate the requests I receieve?

Thanks so much,