How do we deliver an automated message if we do not respond after x seconds?

How do we deliver an automated message if we do not respond after x seconds?

Scenario: A website visitor starts a chat. We have not responded within, let's say 60 seconds. How do we trigger a message asking them to leave a message and we will get back to them. I found *where* to enter such a message. But not how to trigger it if we do not respond within a given time period.

Thanks