Is there a reason you can’t have root on your VPS? Maybe you could ask to have Jellyfin and ffmpeg installed by an admin?
If your willing to try it, you could unpack the .deb file with dpkg -x <jellyfin-ffmpeg-for-your-distro.deb><unpackdir> and stick the resulting directory (directories?) in Jellyfin’s PATH, but I’ve never tried this myself and I don’t know how well this could work.
The docs say jellyfin-ffmpeg is only needed on Debian distros, like Debian itself or Ubuntu, other distros like Fedora should be able to use their respective ffmpeg packages. https://jellyfin.org/docs/general/installation/linux#ffmpeg-installation
Is there a reason you can’t have root on your VPS? Maybe you could ask to have Jellyfin and ffmpeg installed by an admin?
If your willing to try it, you could unpack the .deb file with
dpkg -x <jellyfin-ffmpeg-for-your-distro.deb> <unpack dir>
and stick the resulting directory (directories?) in Jellyfin’s PATH, but I’ve never tried this myself and I don’t know how well this could work.