If you mean that you are using Proton VPN on your Raspberry Pi to mask your downloading traffic, then no that same VPN will not help you access services like Jellyfin on your home network while you are remote.

Instead you’ll want to use something like Tailscale (or Wireguard). You run it as a service on your home network and it then becomes your own VPN that you (or others) can use to connect to your home network when you are remote.

You could run Wireguard on the same RaspberryPi that you use for downloading but I would recommend against it assuming that you’re running Proton VPN right on the host itself (and not inside a container).