There is only an entry when a plugin is installed. Installing from omv-extras on OMV 5.x is only installing docker. There is an option to install portainer which is the web interface that is replacing the docker plugin. Then you click the button to go to the portainer web interface.
Thanks. Just did that, works well. Quick question on Portainer, on the network it uses "bridge", but gives it a 172. ip address. Is there a method to pass through and pick up an address from my network? Apologize for the question, new(er) to Docker.