Typically at the bottom of websites you'll see something along the lines of "© Website Name 2023. All Rights Reserved".
While you can hard-code this piece of content in your footer, I recommend you actually inject the year using a small amount of JavaScript.
That way, when New Years comes around, you can spend your time partying instead of updating your website's footer to reflect the validity of your copyright 😉.
In HTML, you can very quickly do this by using the following snippet:
<footer>
<p>© Website Name <span data-year></span>. All Rights Reserved.</p>
</footer>
<script>
document.querySelector("[data-year]").textContent = new Date().getFullYear()
</script>
If you're using a frontend library like React, it's even simpler!
<footer>
<p>© Website Name {new Date().getFullYear()}. All Rights Reserved.</p>
</footer>