Hey @awesumpunk! Sorry to say, but I don't understand your question. Here are some words that are probably irrelevant but potentially useful for others.
The WebHook URLs look pretty simple and are formatted like any other URL. Our WebHooks are triggered when a datapoint is added (or edited, or deleted) on Beeminder, i.e. they're outbound rather than inbound. If you wanted inbound, that's the Beeminder API.
If you're confused at my confusion, then my own callback URLs look like this:
http://example.com/bmndr/callback, with any of the components changed to match your webserver and endpoint. It gets set on the goal's terrifyingly advanced settings page.
For calling into Zapier with a WebHook, according to the WebHook zap help page, theirs look like
https://zapier.com/hooks/catch/n/Lx2RH/ which you should be able to copy from the zap that you set up.