palaѕн

let count = 1;
function addElement(e) {
  e.preventDefault();
  //let text = $('#itemToAdd').val();
  let newItem = $(`<li>This is a text ${count++}  </li>`);
  let removeBtn = $('<button>X</button>');

  newItem.append(removeBtn);
  $('#shoppingList').append(newItem);
  //$('#itemToAdd').val('');    
}

$(document).ready(function() {
  $("#addBtn").on('click', addElement);

  $('#shoppingList').on("click", "button", function(event) {
    $(this).closest('li').remove();
  });
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<button id="addBtn">Add</button>
<ul id="shoppingList"></ul>