How to add a notification sound for incoming SMS in Twilio Flex

Question

I'm working on a Flex plugin and trying to get a notification sound to play when a new SMS is accepted, very similar to how a sound is played when a call is accepted. This is where I'm at:

manager.workerClient.on("reservationCreated", (reservation) => {
      if(reservation.task.taskChannelUniqueName === 'sms') {
          flex.AudioPlayerManager.play(
          {
            url: "twiml link",
            repeatable: false
          });
       }
});

Not entirely sure where to go from here.