无法使用twilio视频访问参与者曲目

我正在尝试使用twilio视频api实现一个两人视频调用。我似乎无法访问任何参与者的音频/视频曲目，无论是已经在房间中还是通过参与者连接的回调。我试图从新加入的参与者那里访问曲目的代码是：

Twilio.Video.connect(token, {name:room_name}).then(function(room) {
  console.log('Successfully joined a Room:');
  //console.log(room);
  room.on('participantConnected', function(participant) {
    console.log('A remote Participant connected:');
    console.log(participant.sid);
    participant.tracks.forEach(track => {
      //This does not get added and the console.log doesn't fire.
      console.log('adding track');
      document.getElementById('videoRow').appendChild(track.attach());
    });
  });
});

谢谢你的帮助

找到显示如何添加参与者曲目的