JSFiddle - React, Tailwind, and code Playground

HTML

<div id="testTimer">

</div>

JavaScript

function Timer() {
  var counter = 10;
  var myTimer = setInterval(function() {
    document.getElementById("testTimer").innerHTML = counter;
    counter--;
    if (counter < 0) {
      clearInterval(myTimer);
      document.getElementById("testTimer").style.color = "red";

      // do anything then time is up. ex: submit() function
      document.getElementById("cntnt01moduleform_1").submit();
    }
  }, 1000);
}
Timer();