$(document).ready(function() {
  $('.item').magnificPopup({
      type:'image',
      delegate : 'a',
      gallery : {
        enabled : true
      }
  });
});


jquery - cdn

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.3/jquery.min.js" integrity="sha512-STof4xm1wgkfm7heWqFJVn58Hm3EtS31XFaagaa8VMReCXAkQnJZ+jEy8PCC/iT18dFy95WcExNHFTqLyp72eQ==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/magnific-popup.js/1.1.0/jquery.magnific-popup.min.js" integrity="sha512-IsNh5E3eYy3tr/JiX2Yx4vsCujtkhwl7SLqgnwLNgf04Hrt9BT9SXlLlZlWx+OK4ndzAoALhsMNcCmkggjZB1w==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>

Css - cdn

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/magnific-popup.js/1.1.0/magnific-popup.min.css" integrity="sha512-+EoPw+Fiwh6eSeRK7zwIKG2MA8i3rV/DGa3tdttQGgWyatG/SkncT53KHQaS5Jh9MNOT3dmFL0FjTY08And/Cw==" crossorigin="anonymous" referrerpolicy="no-referrer" />