JSFiddle - React, Tailwind, and code Playground

HTML

<fieldset id="myFieldSet">
</fieldset>

JavaScript

function buttonClicked() {
    var el = document.createElement("<p>");
    el.appendChild(document.createTextNode("Test");
                   
    var tmp = document.createElement("div");
tmp.appendChild(el);
                   
    var fieldSet = document.getElementById("myFieldSet");
    fieldSet.innerHTML = tmp.innerHTML;
}