Working on a storage website, I have to append jquery to create a new div section which is same as the first part of div, and so with them a unique identifier in the class and data attribute. I'm trying to call the keyin and undo button that is a unique identity to each newly created div.
I've tried adding the below before the click function, but the result comes back as data item 1 and won't go beyond.
var number = $('.product-item').data('item');
$(document).ready(function() {
 function ctrlSerial() {
  var number = $('.product-item').data('item');
  $('.keyin_ctrl_' + number).on('click', function() {
   var item = $(this).data('item');
   var result = $('.serial_' + item).val() + '\n';
   $('.display_' + item).append(result);
   $('.serial_' + item).val('');
   $('.serial_' + item).focus();
  });
  $('.undo_ctrl_' + number).on('click', function() {
   var item = $(this).data('item');
   $('.display_' + item).html('');
  });
 }
 $('#add_product').on('click', function() {
  var itemNo = $('.product-item').length + 1;
  var product = '<div class="product-item" id="product-' +
   itemNo + '" data-item="' + itemNo + 
   '"><span>#' + itemNo + '</span><br><input class="form-control serial_' +
   itemNo + '" maxlength="25" placeholder="Key in Serial Number and hit button Key In">'
   + '<button class="btn btn-dark keyin_ctrl_' + itemNo + ' keyin_ctrl" data-item="' + 
   itemNo + '" type="button">Key In</button><button class="btn btn-dark undo_ctrl_' + 
   itemNo + ' undo_ctrl" data-item="' + itemNo + '" type="button">Del</button>' + 
   '<br><textarea class="form-control display_' + itemNo + 
   '" name="products[0][serialnumbers]" rows="5" style="resize: none;"' + 
   'placeholder="eg. SGH8484848" readonly></textarea></div>';
  $('#append').append(product);
  ctrlSerial();
 });
 ctrlSerial();
});<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<button type="button" id="add_product" class="btn btn-dark">
Add Product <i class="fas fa-plus-square"></i>
</button>
<hr>
<div id="append">
 <div class="product-item" id="product-1" data-item="1">
  <span>#1</span><br>
  <input class="form-control serial_1" maxlength="25" 
placeholder="Key in Serial Number and hit button Key In">
  <button class="btn btn-dark keyin_ctrl_1 keyin_ctrl" 
       data-item="1" type="button">key in</button>
  <button class="btn btn-dark undo_ctrl_1 undo_ctrl" 
       data-item="1" type="button">del</button>
   <br>
   <textarea class="form-control display_1" name="products[0][serialnumbers]" rows="5"
 style="resize: none;" placeholder="eg. SGH8484848" readonly></textarea>
 </div>
</div>I am supposed to be able to key in on the 2nd added product.
 
     
    