JSFiddle - React, Tailwind, and code Playground

HTML

<div id="my-field">
  <div class="grey-field">
    <!--box i want to clone -->
    <div class="my-row">
      <a class="button add-row">11</a>
      <a class="button remove-row">22</a>
    </div>
  </div>
</div>

JavaScript

$('.add-row').on('click', function() {
  var row = $(this).parent().clone(true);
  row.removeClass('my-row').css('display', 'none');
  row.insertBefore('#my-field .grey-field>div:last').fadeIn('slow');
  return false;
});

$('.remove-row').on('click', function() {
  $(this).parent().fadeOut(600, function() {
    $(this).remove();
  });
  return false;
});