Hi @juanjoaranzales !
Welcome to the forum!
The error message says the h1 needs a closing tag.
It would help to see your code though.
When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make it easier to read.
You can also use the “preformatted text” tool in the editor (</>) to add backticks around text.
See this post to find the backtick on your keyboard.
Note: Backticks (`) are not single quotes (’).