Have you followed all the steps?

Yes and called them. They said because it's a Plex server my Nvidia Shield I need to try and access it it through a PC but unfortunately I only have a work laptop and I'm unable to install anything on. So I have to try it through the Android app and it just isn't workings for me. I've added Plex to Sonos for a work around but it compresses the file to 16bit. Tied "//<ip address>/music" where the music is but won't do anything