Learn HTML by Building a Cat Photo App - Step 1

Tell us what’s happening:
I put the prompt in between where it told me but I cannot progress any further, when I select check code nothing happens.

  **Your code so far**
<html>
<body>
  <h1>CatPhotoApp</h1>
</body>
</html>
  **Your browser information:**

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.5 Safari/605.1.15

Challenge: Learn HTML by Building a Cat Photo App - Step 1

Link to the challenge:

Have you tried restart the page?