hi my name is kaviya. I had the same issue.
" You have made a mistake over here.
You are asked to indent the h2 element, the comment, and p element exactly two spaces to indicate they are children of the main element.
Since you have made some changes, I recommend you to click restart step.
Then, You can do the challenge by adding two spaces before the elements
or, by selecting the h2 element, the comment, and p element and then pressing the tab key once."
try this it worked for me. I got this when I was searching online about this