Moving Page Number tool in header

I have created a custom element
for page number and using prepopulate the value with current page number
and total page number. But how can i change the page number value
when i change page using scroll down or going to next page. Is there any event
we get when page changes so that i can update my value in custom element?

If i am having the wrong approach please correct me? Below is the code for reference.

header.push({

  type: 'customElement',

  title:'Page',

  render: function() {

    var slider = document.createElement('input');

    slider.type = 'text';

    slider.value = currentPage;

    slider.tabindex="-1";

    slider.style="width: 11.5px; border:none; font-size: medium; margin-top: -1px;";

    slider.oninput = function() {

      console.log('---oninput---');

    };

    slider.addEventListener("keyup", function(event) {

      console.log('---keyup---');

    });

    var pageNum = document.createElement('input');

    pageNum.type = 'text';

    pageNum.value = " /  " + TotalPageNumber;

    pageNum.tabindex="-1";

    pageNum.style="width: 30px; border:none; font-size: medium; margin-top: -1px;";

    pageNum.oninput = function() {

      console.log('---oninput---');

    };

    pageNum.addEventListener("keyup", function(event) {

      console.log('---keyup---');

    });

    var form = document.createElement('div');

    form.style="display: flex; border-radius: 10px;padding: 10px;cursor: pointer;";

    form.appendChild(slider);

    form.appendChild(pageNum);

    return form;

    // return slider;

  }

});

Regards
Abhishek Maurya