This article explains how to add Spotify to a Roku streaming device or Roku TV. All Roku TVs and Roku streaming devices with a model number of 3600 or later are compatible with the upgraded Spotify app.
How to Get Spotify on a Roku TV
Add the Spotify app from the Roku Channel Store using your Roku device or Roku TV remote.
From the Roku home screen, select Streaming Channels.
Select Search Channels.