Probably the most reliable way to share files is with NFS. See https://wiki.debian.org/NFSServerSetup and https://wiki.archlinux.org/title/NFS#Server_configuration for a guide.
You can quickly share files with python:
python -m http.server 8000
For setting up quick download/upload access you can use shareboxx. SIngle binary web UI.
HTTP File Server (HFS) can host a directory, upload is possible as well.