Redhat is trying had to establish Podman as a replacement for Docker, by pushing it as default container engine for Redhat Enterprise products (RHEL, Openshift…).
Sadly, as of today, there is no support for Podman Checks in CMK.
Although there is some compatibility to Docker (docker commands can be aliased to podman), the Docker python module, which agent plugin uses, does not work with Podman.
So a new agent plugin would be needed for Podman support.