WatchGuard Firebox Cloud offers subscriptions for various security services that help keep your network and instances secure. The full suite of all security services can be purchased in a packet called Total Security. More information can be found on the WatchGuard web site:
The WatchGuard Firebox Cloud BYOL (bring your own license) AMI includes all the services. To get a WatchGuard Firebox Cloud License contact a WatchGuard partner. The WatchGuard Firebox Cloud Pay As You Go AMI has some limitations at this time. Likely the Pay As You Go AMI will have all services in the near future. For more information refer to the WatchGuard Firebox Cloud documentation.