JSFiddle - React, Tailwind, and code Playground
HTML
<form>
<textarea id="tpName" name="tpName" onchange="tpName(this)" style="margin-top: -9px; width: 275px; height: 40px;"></textarea>
</form>
<textarea id="copytpName" name="copytpName" style="margin-top: -9px; width: 275px; height: 40px;"></textarea>
JavaScript
$("#tpName").keyup(function(){
console.log("adaad");
$("#copytpName").val($(this).val());
})