Virtualmin Remote API Does Not Change Administrator Group

I have been using the Remote API to administer my Virtualmin Server.

When I change a domain's username, the API does not change the administrator group as well. Though, when I change the username via the Web Interface, the administrator group gets updated.

I don't see a specific API parameter to change the administrator group in addition to the user.

Here is the CLI output:

root@slacky:~# virtualmin modify-domain --domain domaintest.com --user test
Updating virtual server domaintest.com ..

Modifying administration user .. .. done

Changing username in website configuration .. .. done

Updating user and group in Logrotate configuration .. .. done

Renaming MySQL user .. .. done

Renaming Webmin user .. .. done

Updating user to run AWstats report as .. .. done

Saving server details .. .. done

Updating Webmin user .. .. done

Applying web server configuration .. .. done

Re-loading Webmin .. .. done

All done

As you can see in the output, it does not show that it is updating the administrator group as in the web interface.