Square "Watch New Events" module looks like it returns successfully but the is no URL

I am trying to use the Square “Watch New Events” module.

When configuring, I click “Add”. I name the webhook, verify the connection and click Save.

The Create a webhook pop-up closes. On returning, there is the webhook name I entered. But no URL shown (see below). If i click “Copy address to clipboard” nothing is copied. I can click save. If I go look at the webhooks, it is there with no URL.

I have been able to use the same connection successfully with other non-webhook modules.

Any suggestions?