title: LoopBack Storage Service: how to use upload/download methods from js code?
body: <p>How can I upload/download files in the simplest way using <em>storageService.upload</em> and <em>storageService.download</em> function from my JavaScript/Loopback code? I'm trying do something like that:</p>
  
  <pre><code>app.post("/sendFile", (req, res) =&gt; client.upload( req, res, {}, () =&gt; {console.log("cb")} ) );
  </code></pre>
  
  <p>But this doesn't work. I make my REST request with Advanced Rest Client Application in Google Chrome. I set <em>Content-Type</em> for <em>multipart-form-data</em> and add my jpg file in files section. </p>
  
  <p>I got <em>Failed to create a multipart upload on S3: {"message":"Missing required key 'Bucket' in params","stack":"MissingRequiredParameter: Missing required key 'Bucket' in params (...)</em> error. </p>
  
  <p>I'm newbie here, but I have impression that <a href="https://apidocs.strongloop.com/loopback-component-storage/#storageservice-prototype-upload" rel="nofollow">Loopback documentation</a> should be much better. Thanks for help!</p>