Hello,
in the QLog wiki, the path for the QLog backup files, the database and the settings is specified under "Autobackup".
The information does not apply if QLog is installed as a Flatpak. In Linux-Mint you can find the database for example under "~/.var/app/io.github.foldynl.QLog/data/hamradio/QLog"
I do not know whether this is the case in all cases. Maybe you could add the paths in the wiki at this point.
73, Wolfgang
DL2KI