continue count down after refresh

Question

The counter works properly but starts again after refresh How can I continue after refreshing the counter?

function startTimer(duration, display) {
    var timer = duration, minutes, seconds;
    setInterval(function () {
        minutes = parseInt(timer / 60, 10);
        seconds = parseInt(timer % 60, 10);
  
        minutes = minutes < 10 ? "0" + minutes : minutes;
        seconds = seconds < 10 ? "0" + seconds : seconds;
  
        display.textContent = minutes + ":" + seconds;
  
        if (--timer < 0) {
            timer = duration;
        }
    }, 1000);
  }
  
  window.onload = function () {
    var duration = 60 * 2,
        display = document.getElementById("timer");
    startTimer(duration, display);
  };

Answer 1

you can try and use localStorage. localStorage is similar to sessionStorage, except that while data stored in localStorage has no expiration time, data stored in sessionStorage gets cleared when the page session end. for example:

localStorage.setItem("duration",60);
localStorage.getItem("duration"); //60

check out this documentation: https://developer.mozilla.org/en-US/docs/Web/API/Window/localStorage