Ready API license on EC2 Spot Instances

I want to understand how ReadyAPI licensing works on ephemeral EC2 Spot instances. The Spot instances are part of our CI/CD pipelines, where one of stages in pipeline is ReadyAPI based testing.
Since the spot instances are ephemeral, how does the licensing help in this case?

Is my understanding right that we can activate license on an instance with Elastic IP address, and re-use this Elastic IP address with different EC2 machines? If so, will the private IP address have any impact on this procedure when Elastic Public IPs are used?