title: Convert audio from url to base64 in nodejs?
body: <p>I want to send a voice clip to facebook messenger and have it translated to text using Google Cloud Speech to text. However, facebook messenger format set the url to the file, and I have no idea to convert it to base 64. If it's an image like .png and .jpg, it's fine, there are packages for that. But I am trying to convert audio like .mp3 and .m4a files. Is there any tool for that to work with nodejs.</p>
  
  <p>I would prefer not to save the audio file as a local file, beause I am deploying a server using Google App Engine, and doing so will just make the matter super complicated.</p>