Can't seem to find jellyfin-web folder

[Efficient_Good_5784]

Hey, I'm also running Jellyfin (10.10.7) in CasaOS but I don't have a Jellyfin folder after /usr/share

Any idea why it's missing/how to add it?

You need to search for it inside the Jellyfin docker container.
A container contains all the files for a image to run and use.
Unless you host mounted something from the outside, it will all be inside the container.