JSFiddle - React, Tailwind, and code Playground

HTML

<input type='text' id='phone-number'>
<div class='phone-number'></div>

JavaScript

$('#phone-number').val('78908');
$('#phone-number').on("keyup change", function () {
    var pnumber = $(this).val();
    $('.phone-number').text(pnumber)
});
$('#phone-number').change();