JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.2/css/select2.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.2/js/select2.full.min.js"></script>
<div class="idevele">
</div>

JavaScript

var html = '\
<div class="ismetlendo">\
	<label>Termék:</label>\
	<select class="oh_please_call_select2_on_me" name="termek[]">\
		<option>Termék lista</option>\
  </select>\
  <input type="number" name="price[]">\
</div>';
var $root = $('.idevele');

var callPlugins = function ($onThis) {
	$onThis.find('.oh_please_call_select2_on_me').select2();
};

var callAjax = function () {
	setTimeout(function () {
  	handleAjax(html);
  }, 500);
};

var handleAjax = function (response) {
	var $response = $(response);
  callPlugins($response.clone().appendTo($root));
  
  $('<button>').text('Klónok előre')
  	.prependTo($root)
    .on('click', function () {
      callPlugins($response.clone().appendTo($root));
    });
};

callAjax();