download audio recording in sms google voice

download_audio.js

document.querySelectorAll('audio').forEach((au) => {
  const url = au.currentSrc;
  fetch(url).then(r => r.blob()).then(obj => downloadAudio(obj));
})

function downloadAudio(blob) {
  const ele = document.createElement('a');
  let counter = 0;

  downloadAudio = function (blob) {
    ele.download = "Audio" + ++counter;
    ele.href = URL.createObjectURL(blob);
    ele.click();
  }

  downloadAudio(blob);
}