Welcome to the forum @HJvD
In other words, you need to look at the recommendations of whatever you’re running. Some databases respect VSS, and may make good backups with Duplicati’s snapshot ability. Others don’t support VSS.
The problem is that database programs keep data in memory. Until forced to files, backups can’t get it.
Shadow Copy Creation for Providers is the complicated dance which a VSS-aware service aims to do.
Windows VSS is not guaranteed to work. Service stop or promised-reliable-while-active backup is best. This sense of the word “backup” is to take the active database and dump it into static files for a backup.
Although you obscured portions of total path, I wonder if this is an H2 database (has the .mv.db suffix)?
H2 Database Engine may fit if you use that as a Windows Service. If it’s in an app, what does app say?
If you find your DB does not support VSS, then the alternative is to have it “backup” to files in the way it considers active-safe (possibly orchestrating with scripting options), then take a file backup of its output.