Spotify update adds Siri support on iOS 13, Apple TV app released too
After applying the latest update, simply say “Play [artist] on Spotify” and your iOS 13-powered device should do the rest. Be sure to mention Spotify though, otherwise, Siri will start Apple Music by default.
Another important new addition is Apple TV support, which means that you can now download the app via the tvOS App Store or enable “automatically install apps” in tvOS settings to install it.
Last but not least, Spotify has introduced low data mode on iOS 13. Basically, this means that the app will now turn on Data Saver when your iOS device's Low Data Mode is turned on.
All the improvements added in the update should work with all the devices running iOS 13, but 9to5mac discovered that the HomePod does not recognize Siri song requests yet. The issue might be addressed in a future iOS update, so you might want to try again after iOS 13.2 gets released.