title: Postman can download / display pdf but browser cannot
body: <p>I have an endpoint that decodes a base64 pdf string, creates a buffer out of it, then sends that buffer back as the response. I have the headers set to:</p>
  <pre><code>Content-Type: application/pdf
  Content-Disposition: attachment; filename=&quot;&lt;my_filename&gt;.pdf&quot;
  </code></pre>
  <p>When I hit this endpoint from postman, it correctly shows / downloads the pdf (depending on if I do send or send and download). However, if I hit this endpoint from my react app, it doesn't start the download. I don't have popups blocked and I am receiving the buffer from the request.</p>
  <p>I've tried not decoding the base64 string and sending the response back like:</p>
  <pre><code>res.status(200).send(`data:application/pdf;base64,${base64String}`);
  </code></pre>
  <p>but that didn't work for either postman or the browser.</p>
  <p>I'm not sure what I'm missing here. If postman is correctly getting the information it needs to both display and download the pdf, I can't imagine I'm too far from getting the browser to be able to do the same.</p>