Can't set just ebook-convert binary

[tuxArg]

Hi,

I have download calibre as instructed here: https://calibre-ebook.com/download_linux
Using the isolated alternative as I don't want to run it as root:
wget -nv -O- https://download.calibre-ebook.com/linux-installer.sh | sh /dev/stdin install_dir=~/calibre-bin isolated=y

I can see all files were actually placed under ~/calibre-bin and I can test it:

$ ~/calibre-bin/calibre/ebook-convert --version
ebook-convert (calibre 7.18.0)
Created by: Kovid Goyal <[email protected]>

I have a working calibre-web installation and would like to add ebook conversion capability, but when setting the calibre binaries path to /home/calibre-web/calibre-bin/calibre this error toast is shown "Calibre binaries not viable".
I have enabled debug log level but just this line is being logged:
[2024-09-23 10:21:18,145] ERROR {cps.admin:1867} Calibre binaries not viable
And this is right as I can't run /home/calibre-web/calibre-bin/calibre/calibredb because of missing libraries I don't want to install

If I only set the ebook-convert binary path, no conversion options are shown in web UI.

So, is it possible to set up only ebook-convert option but no calibre binaries path? Is calibredb really needed if I only want to do ebook-convert?

Thanks

[Xjocinx]