ni Sidney

1. Press the Home button on your remote, and select the LG Content Store.
   
   
2. Select Apps & Games.
   
3. Look through the list, and select Spotify.
   
4. Select Install on the left.
5. If still fails, you can try to download Spotify Music Converter to listen to Spotify music.You just need to copy and paste your downloaded Spotify music files from your computer to your USB flash drive or upload them to your Google Play Music Library.

Sound that it's a good method to download Amazon Music Converter to convert Amazon Prime Music to MP3 then listen on LG TV ,but I haven't try yet.

Because the weak connection. so I download Spotify Playlist to MP3 by using  Spotify Music Converter then listen offline directly.