That script will not work for you.
There are two types of scripts in an Airtable base: scripting extension and automation scripts.
It looks like you wrote your script in scripting extension. These scripts only run when a person pushes a button in the base (either the button for the extension itself or a button field in a data view). These scripts cannot be triggered from outside the base.
Automation scripts run as part of an Airtable automation. These scripts run when the automation itself is triggered. It is possible to trigger an automation with a webhook, but that not going to work either. The automation script does not have a way of returning a value as a response to the code calling the webhook. There is usually a several second delay between triggering the automation and the automation actually running. Each time the webhook is called uses an automation run, and you get a limited number of automation runs per month.
You should also take into account the fact that any public image URLs for an attachment image will expire in a few hours.
Typically , when an outside source wants a random Airtable record, that outside source must handle the randomness itself.
I’ve never used Bravo, so I cannot help you on that side.
