Hi,
thank you. Works for me too.
You could add the commad to extract the files into the game folder.
sudo tar -xvzf /path/to/vs_client_linux-x64_*.tar.gz -C /var/lib/flatpak/app/at.vintagestory.VintageStory/current/active/files/extra/
options:
x - extract files from an archive
v - verbosely list files processed
z - filter the archive through gzip
f - use archive file or device ARCHIVE
C - change to directory DIR