hugo-theme-wondermod/layouts/partials/footer.html

<footer class="footer">
    <span>&copy; {{ now.Year }} <a href="{{ "" | absURL }}">{{ .Site.Title }}</a></span>
    <span>&middot;</span>
    <span>Powered by <a href="https://gohugo.io/" rel="noopener" target="_blank">Hugo️️</a>️</span>
    <span>&middot;</span>
    <span>Theme️ <a href="https://github.com/adityatelange/hugo-PaperMod" rel="noopener"
            target="_blank">PaperMod</a></span>
</footer>
<a href="#top">
    <button class="top-link" id="top-link" type="button">
        <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 12 6">
            <path d="M12 6H0l6-6z" /></svg>
    </button>
</a>

{{ $highlight := resources.Get "js/highlight.min.js" | minify | fingerprint}}
<script src="{{ $highlight.Permalink }}" integrity="{{ $highlight.Data.Integrity }}"></script>
<script>
    hljs.initHighlightingOnLoad();
    document.querySelectorAll('a[href^="#"]').forEach(anchor => {
        anchor.addEventListener("click", function (e) {
            e.preventDefault();

            document.querySelector(this.getAttribute("href")).scrollIntoView({
                behavior: "smooth"
            });
        });
    });
    var mybutton = document.getElementById("top-link");
    window.onscroll = function () {
        if (document.body.scrollTop > 800 || document.documentElement.scrollTop > 800) {
            mybutton.style.visibility = "visible";
            mybutton.style.opacity = "1";
        } else {
            mybutton.style.visibility = "hidden";
            mybutton.style.opacity = "0";
        }
    };
</script>