JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="money" value="12345678.90" />
<p>Change the value to see it work</p>

JavaScript

Number.prototype.formatMoney = function(c, d, t){
var n = this, c = isNaN(c = Math.abs(c)) ? 2 : c, d = d == undefined ? "," : d, t = t == undefined ? "." : t, s = n < 0 ? "-" : "", i = parseInt(n = Math.abs(+n || 0).toFixed(c)) + "", j = (j = i.length) > 3 ? j % 3 : 0;
   return s + (j ? i.substr(0, j) + t : "") + i.substr(j).replace(/(\d{3})(?=\d)/g, "$1" + t) + (c ? d + Math.abs(n - i).toFixed(c).slice(2) : "");
 };


$('#money').on('change', function () {
    var val = parseFloat(this.value);
    this.value = val.formatMoney(2, '.', ',');
});