You appear to have created this post without editing the template. Please edit your post to Tell us what’s happening in your own words.
Learning to describe problems is hard, but it is an important part of learning how to code.
Also, the more you say, the more we can help!
you wrote too much stuff, you need to change the content of the h1 element from Hello World to CatPhotoApp, you can reset the step to restore the original code
You appear to be using a browser extension that is modifying the page. Be sure to turn off all browser extensions. I don’t know what extension may cause it. However, the tag appears in the console, but I can continue.