I am also an author of the new EKS Quick Start for CDK and included an updated version of this example in that as a demo-app that works together with the wider EKS template there.

Refer to https://github.com/aws-quickstart/quickstart-eks-cdk-python and https://github.com/aws-quickstart/quickstart-eks-cdk-python/tree/main/demo-apps#ghost

That also includes an example of how to do the new Flux v2 (as opposed to the v1 here) for deploying OPA Gatekeeper - https://github.com/aws-quickstart/quickstart-eks-cdk-python/blob/main/gatekeeper.md