There is a timer that appears on the screen after clicking .exitA, 1st button.

I want the timer to start after that button is clicked.

https://jsfiddle.net/87jvr3uh/

Right now, it stops after that button is clicked.

    <h2>Click anywhere to stop the timer</h2>

<p id="timer"></p>

<script>
  let seconds = 0;
  let timerId = setInterval(updateTimer, 100);

  function updateTimer() {
    seconds += 0.1;
    document.getElementById("timer").innerHTML = seconds.toFixed(1) + " seconds";
  }

  document.body.addEventListener("click", function() {
    clearInterval(timerId);
    document.getElementById("timer").innerHTML += " (stopped)";
  });

</script>

Here is the standalone timer code by itself:

https://jsfiddle.net/o4qLxnr8/2/