Tell us what’s happening:
Describe your issue in detail here.
Your code so far
<h1>Hello World</h1>
Your browser information:
User Agent is: Mozilla/5.0 (iPhone; CPU iPhone OS 14_4 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/95.0.4638.50 Mobile/15E148 Safari/604.1
The code you have shared works on my end. Please ensure that you have disabled any extensions that interface with the freeCodeCamp website (such as Dark Mode and Ad Blocker), and set your browser zoom level to 100%. Both of these factors can cause tests to fail erroneously.
Also, since you are using a phone the default keyboard does not always play well with the freeCodeCamp editor. I recommend you read the article on using a mobile device to view some tips - most importantly, check out the coding keyboards listed as they interface with the editor well.