It’s better to install into one of the recommended OSs.
openmediavault is a NAS management system. A quick look at their 3rd party plugins shows they are related to file management and image processing tools. I don’t see anything about running web apps.
However the forum has user guides regarding installing Docker. https://forum.openmediavault.org/index.php?thread/40489-how-to-docker-in-omv/
Passbolt offers a Docker install method. You could ask their forum for more guidance about installing Docker and if that goes well, try the passbolt Docker method.