Reinstall Docker button throws error `no installation candidate`

[SplinterHead]

I have a fresh OMV7 install (7.4.3-1) and have installed the latest version of this plugin. When I set up the paths, save it and hit Reinstall Docker button, get the following error. It seems like the Docker repositories haven't been configured, is there some prerequisite work that I need to do before installing Docker via this plugin?

500 - Internal Server Error
Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C.UTF-8; export LANGUAGE=; omv-salt deploy run --no-color compose 2>&1' with exit code '1': debian: ---------- ID: configure_etc_docker_dir Function: file.directory Name: /etc/docker Result: True Comment: The directory /etc/docker is in the correct state Started: 09:24:16.483691 Duration: 1.444 ms Changes: ---------- ID: /etc/docker/daemon.json Function: file.serialize Result: True Comment: File /etc/docker/daemon.json is in the correct state Started: 09:24:16.485250 Duration: 57.159 ms Changes: ---------- ID: docker_install_packages Function: pkg.installed Result: False Comment: Problem encountered installing package(s). Additional info follows: errors: - Running scope as unit: run-r050c250dd9fa4848809ff6bef5a531b1.scope E: Package 'docker-ce' has no installation candidate Started: 09:24:17.506163 Duration: 4529.139 ms Changes: ---------- ID: docker_compose_install_packages Function: pkg.installed Result: False Comment: Problem encountered installing package(s). Additional info follows: errors: - Running scope as unit: run-r5f37d7db9e3a4b558906b1e5ac427057.scope E: Package 'docker-compose-plugin' has no instal...

It works successfully after adding the Docker apt repositories manually, as described on the Docker docs. Is this supposed to be within the scope of the plugin?

[ryecoaaron]

The docker repos are added in omv-extras by checking the Docker checkbox. This is documented here - https://wiki.omv-extras.org/doku.php?id=omv7:omv7_plugins:docker_compose