If I’m not mistaken, the JS method of adding a custom footer to your blog would help you accomplish this, no? Here’s the most official of a bunch of threads on this forum detailing the process…
If it helps, here is the entirety of what’s delivering the footer of my blog as of this moment within its “Custom JavaScript” text field:
var topP = document.createElement("p");
//topP.style.textAlign = "center";
topP.innerHTML = '<hr><div class="custom-nav"><a rel="me" href="https://tiny.write.as/bilge">Tiny</a> ※ <a href="https://twitter.com/NeoYokel">Twitter</a> ※ <a href="https://mastodon.social/@DavidBlue">Mastodon</a> ※ <a href="https://github.com/extratone/bilge">GitHub</a> ※ <a href="https://gist.github.com/extratone/140a11428b5dd1dda500b3928e0438b1">License</a></div>';
var cont = document.getElementById("wrapper");
if (cont !== null) {
// Add to blog index and tag pages
cont.appendChild(topP);
} else {
// Add to individual blog post page
cont = document.getElementById("post-body");
cont.insertAdjacentHTML("afterend", topP.outerHTML);
}