No it doesn't. There may be a way to rig it, but UrBackup was primarily designed for client backup - not to backup the server it's running from.
There's two back up considerations for OMV: The Operating System and the Data drive.
In the following, I'm going to assume you're booting your odroid from a USB drive or an SD-card:
Take a look at this guide. Starting on page 57, data drive backup concepts are covered.
Beginning on Page 62, how to do an easy backup of the Operating System is explained.
Additional options for backing up the OS are available using the openmediavault-backup plugin.
Good backup takes the "drama" out of computing
Primary: OMV 3.0.99, ThinkServer TS140, 12GB ECC, 32GB USB boot, 4TB+4TB zmirror, 3TB client backup.
Backup: OMV 4.1.9, Acer RC-111, 4GB, 32GB USB boot, 3TB+3TB zmirror, 4TB Rsync'ed disk
2nd Data Backup: OMV 3.0.99, R-PI 2B, 16GB boot, 4TB WD USB MyPassport - direct connect (no hub)