How does "watch transaction" trigger work with scenario scheduling?

I am looking to use the “Watch transactions” trigger with Etsy to add sale records to an airtable database. But I’m a little confused about the trigger and how it works together with scheduling the scenario.

It seems from a test run that it only “watches” the transactions when the scenario is running–is that the case? If so, and I want the scenario to be triggered every time an order is placed, how do I make that happen? Do I have to schedule it to run every minute or something? Or is there a way to get the scenario to trigger without specifically being running?

Doing a little more digging, I am seeing that the Etsy “watch” trigger is actually a polling trigger. Is there a way to make a custom webhook for Etsy to get immediate updates?

From what I can see in the Etsy documentation, Etsy does not have webhooks.

Therefore, creating an instant webhook module in the Etsy app isn’t possible, and you also cannot use custom webhooks.