What is a footer?
It's the area of the website usually at the end. Looks like this:

Instructions
Use the <footer> tag after the main content.
You can be creative about what to include there. But if unsure, just the copyright message should be enough. For example:
HTML
<footer class="site-footer">
Copyright © 2024 Site Title
</footer>
CSS
.site-footer {
padding: 8px;
background-color: #000000;
color: #ffffff;
}
(Change the style to what you think looks nice)