There are a lot of different methodes you could try. I think the easiest is to connect both systems with a (mesh)VPN like Wireguard, ZeroTier or Tailscale. Then you can simply copy stuff over using rsync -a (archive mode) with a cronjob or using special tools like Borg backup, kopia, etc

n8n.io is great, but not open source.

I use deemon to download my music from Deezer (free account only supports 128kb/s, this is enough for me though).

For the music server I tried both Jellyfin with the Finamp app and Navidrome with the Tempo app on Android.

For desktop app for both I use SonixD/Feishin (crossplatform)

Both where fantastic solutions but I stuck with Navidrome as it was easier to share playlists. (As an URL for non registered users or as public playlist for all registered users)

My setup is as following: Hypervisor: Proxmox VE NAS: TrueNAS Scale (where all music is stored)

1 LXC container with Deemon installed that downloads music in mounted NFS share from TrueNAS

1 VM with Navidrome installed in Docker with the music folder mounted with NFS

You don’t have to use such a setup, you can perfectly do this on your existing PC with Windows, MacOS or Linux with DE. Or server OS like Linux with CLI, OpenMediaVault, TrueNAS Scale or unRAID