Launching VyOS on AWS as spot instance

I’m subscribed to VyOS in AWS Marketplace. The spot instances checkbox is grayed out when I try to launch an instance. I found a post from 2016 that describes a process for launching spot instances from the Marketplace so I suspect this is a common problem.

https://www.paulwakeford.info/2016/01/07/aws-marketplace-and-spot-instances/

The AWS Marketplace console no longer resembles what the author described in the article.

Has anyone had luck launching VyOS on AWS as a spot instance?