title: CORS policy is allowed in app.py but still not working
body: <p>The front-end app is built on ReactJs and development server is running on <a href="http://localhost:3000" rel="nofollow noreferrer">http://localhost:3000</a>. The back-end API is built with Flask 2.0.2 and is running on <a href="http://localhost:5000" rel="nofollow noreferrer">http://localhost:5000</a></p>
  <p>In app.py file, the CORS has been allowed as mentioned in the <a href="https://flask-cors.readthedocs.io/en/latest/" rel="nofollow noreferrer">documentation</a> like:</p>
  <pre><code>CORS(app, resources={r&quot;*&quot;: {&quot;origins&quot;: &quot;*&quot;}})
  </code></pre>
  <p>When I try to submit the login form I still get the following error:</p>
  <p><a href="https://i.stack.imgur.com/dZSjO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/dZSjO.png" alt="enter image description here" /></a></p>