You don’t want to use HTML tags in the CSS (in other words, in between the style tags), only the name of the element, so you can get rid of the <h1> and </h1> tags. You would replace element above with just the name of the element you are trying to style. So if you were styling a header element than you would replace element above with header.
You did do the property and value correctly, so don’t make any changes there. Based on what I wrote above, give it another try and if you still need help then paste your updated CSS in here so we can see what you did.
To display your code in here you need to wrap it in triple back ticks. On a line by itself type three back ticks. Then on the first line below the three back ticks paste in your code. Then below your code on a new line type three more back ticks. The back tick on my keyboard is in the upper left just above the Tab key and below the Esc key.