@westerni: in addition to what @saidsl advised, you may want to review the following forum threads for more tips/tricks/workarounds
- Download Backup from VirtualBox Installation - #3 by krnkris
- Newbie: How to backup? - #9 by asharamseervi
- "Manage Third Party Backup" option is missing, schedule the database backup and https issue - #2 by saidsl
I hope it may help.