javascript – Countdown timer including digits on IOS 17 units

var timer;
const COUNTER_KEY = 'my-counter';

perform countDown(i, callback) {
  //callback = callback || perform(){};
  timer = setInterval(perform() {
    minutes = parseInt(i / 60, 10);
    seconds = parseInt(i % 60, 10);

    minutes = minutes < 10 ? "0" + minutes : minutes;
    seconds = seconds < 10 ? "0" + seconds : seconds;

    doc.getElementById("displayDiv").innerHTML = minutes + ":" + seconds;

    if ((i--) > 0) {
      window.sessionStorage.setItem(COUNTER_KEY, i);
    } else {
      window.sessionStorage.removeItem(COUNTER_KEY);
      clearInterval(timer);
      callback();
    }
  }, 1000);
}

window.onload = perform() {
  var countDownTime = window.sessionStorage.getItem(COUNTER_KEY) || 600;
  countDown(countDownTime, perform() {
    doc.getElementById("banner-message").model.show = "none";
  });
};