Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

That's what I use for my NAS. I remember with protonvpn you need to pull down the config file for the server you want to use and place it in the proper directory. Here's part of my docker-compose:

  transmission-openvpn:
    cap_add:
      - NET_ADMIN
    volumes:
      - '/DATA/torrents:/data/torrents'
      - '/SSD/config/transmission:/etc/openvpn/custom'
    environment:
      - OPENVPN_PROVIDER=custom
      - OPENVPN_CONFIG=node-us-167.protonvpn.net.udp 
      - OPENVPN_USERNAME=${USERNAME}
      - OPENVPN_PASSWORD=${PASSWORD}
      - LOCAL_NETWORK=192.168.0.0/16
      - OPENVPN_OPTS=--inactive 3600 --ping 10 --ping-exit 60
      - DNS=8.8.8.8,8.8.4.4
    logging:
     driver: json-file
     options:
       max-size: 10m