I don't think the UrBackup client software is capable of triggering a MySQL dump (by default at least) but you can schedule a separate task, event, etc. and time it out and point the UrBackup client to backup the directory which the dump file resides which is the way I handle it on a MySQL instance.
I assume you already know this and understand how
mysqldump works so I'll not post an example or anything unless you want me to but that's what I use to automate the backup to disk operation.
Be sure to tag me back if you hear or determine otherwise as I'd be interesting in understanding some of the detail, but I typically prefer working with MySQL backups with the built-in tools provided rather than 3rd party for the database dump to disk operation.
Please note that I use scheduled
mysqldump CLI scripts and have scheduled tasks trigger the backups each day. I'm in a Windows environment and I use Task Scheduler to trigger the backups but I assume you'd use Linux Cron scheduler or something like that in your case to execute a bash script or something with the