It did not work with VW2019 for me, but this path is the correct one:
/Volumes/Vectorworks\ 2019/Vectorworks\ 2019\ installieren.app/Contents/Resources/installer/Install\ Vectorworks2019.app/Contents/MacOS/installbuilder.sh
Makes it:
sudo /Volumes/Vectorworks\ 2019/Vectorworks\ 2019\ installieren.app/Contents/Resources/installer/Install\ Vectorworks2019.app/Contents/MacOS/installbuilder.sh --unattendedmodeui none --mode unattended --Serial EDMUSA-XXXXXX-XXXXXX-XXXXXX --UserName <name goes here> --CompName <computer name goes here> --installdir <install directory goes here>