I have the spotify app version 18.104.22.1689 and a Premium Account, on an Apple Iphone 6S ios v11.4. In Australia.
I have read about Spotify's Voice Assistant, however I cannot find it in the app. I have pressed on the search magifing glass with no luck, cannot see a microphone anywhere. And when I go into the iPhones microphone settings the Spotify app is not listed.