Indeed, you can install Automatic's Automation Engine (AE) across multiple Linux servers ( to distribute the Load among the servers) or on a Linux Cluster using the cluster's virtual IP adress as hostname.
Since there is no License Checks anymore on version 12.3, you don't need a License for Each node anymore.
Please refer to the documentation below and reach out to your Account Manager in order to verify if your Contract entitles you to use multiple Automation Engine Nodes or High Availability Instances.