If the music is really stored on your phone, there’s two ways to do this. Either you AirPlay you music to the Era using the Apple Music app, see https://support.sonos.com/en-us/article/stream-airplay-audio-to-sonos or you connect your phone to the Era via bluetooth and play the music form the Apple Music app, see https://support.sonos.com/en-us/article/pair-sonos-era-100-with-bluetooth

Storing music on a phone is a very old fashioned concept in this age of streaming music from internet sources. Are you sure your music is on your phone instead of streaming from the internet, either from Apple Music or Spotify for instance? If this is the case, you can add content services to the Sonos app, see https://support.sonos.com/en-us/article/add-a-content-service-to-sonos

Thanks from an old fashioned guy!

I recently To transfered iphone  music library to sons  Era 100,there were many options like  use MusConv.. to move your playlists from Apple Music to a Sonos-supported service like Spotify or Amazon Music. Then, add that service in the Sonos app and control it with voice commands.