wx.cloud.callFunction({
  name: 'music',
  data: {
    musicId,
    $url: 'musicUrl',
  }
}).then((res)=>{
  let result = res.result
  // console.log(result)
  if (result.data[0].url == null) {
    wx.showToast({
      title: '无权限播放',
    })
    return
  }
  //不是同一首才重新加载
  if(!this.data.isSame){
    backgroundAudioManager.src = result.data[0].url
    backgroundAudioManager.title = music.name
    backgroundAudioManager.coverImgUrl = music.al.picUrl
    backgroundAudioManager.singer = music.ar[0].name
    backgroundAudioManager.epname = music.al.name

    console.log(backgroundAudioManager)

    // 保存播放历史
    this.savePlayHistory()
  }

老师，上面的代码， $url: ‘musicUrl’, 是来获取歌曲的信息的把， 怎么调用backgroundAudioManager就可以播放呢，他的音频数据在哪里