Learn HTML by Building a Cat Photo App - Step 1

I’m still doing the first step of creating a “Cat Photo App”, but no matter what I try, it still says the following:

Sorry, your code does not pass. Don’t give up.

You appear to be using a browser extension that is modifying the page. Be sure to turn off all browser extensions.

Your code so far

<html>
  <body>
  <header>
    <h1>CatPhotoApp</h1>
  </header>
  </body>
</html>

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36

Challenge Information:

Learn HTML by Building a Cat Photo App - Step 1

do you have an extension for night mode or forced dark page in your browser make sure to turn that off, vpn and block tracker can cause the same problem