Any FTP server would do, kinda easy to setup, fast (unless you're transferring like 10k 1kb files).
SMB is not recommended, as older versions are kinda vulnurable, modern versions can be good, but i haven't really tried it.
Majority of file managers on Android would support SMB and FTP, Windows and Linux too.
Overall i would recommend looking at FTP server. It's usually easy to setup, and it's good in transferring big files (which is usually what Jellyfin is working with).
NFS is kinda complex to setup, but very fast.
Any FTP server would do, kinda easy to setup, fast (unless you're transferring like 10k 1kb files).
SMB is not recommended, as older versions are kinda vulnurable, modern versions can be good, but i haven't really tried it.
Majority of file managers on Android would support SMB and FTP, Windows and Linux too.
Overall i would recommend looking at FTP server. It's usually easy to setup, and it's good in transferring big files (which is usually what Jellyfin is working with).