title: Proxy in CRA not successful
body: <p>I'm adding a backend to my app (cra typescript), which I serve on port 4000, so I added the line <code>&quot;proxy&quot;: &quot;http://localhost:4000&quot;,</code> to package.json, like described <a href="https://create-react-app.dev/docs/proxying-api-requests-in-development/#configuring-the-proxy-manually" rel="nofollow noreferrer">here</a>.</p>
  <p>Next, I'm running code in my frontend app to hit the endpoint:</p>
  <pre><code>fetch('/hello')
    .then(res =&gt; { console.log('YEAH', res) })
    .catch(err =&gt; { console.warn('NOPE', err) })
  </code></pre>
  <p>But now the console says I'm still hitting port 3000 instead of 4000.</p>
  <p><code>App.tsx:6 GET http://localhost:3000/hello 500 (Internal Server Error)</code></p>
  <p>What am I doing wrong?</p>