Fancybox Blogger original resolution image

<link href='https://cdn.jsdelivr.net/gh/fancyapps/fancybox@3.5.7/dist/jquery.fancybox.min.css' rel='stylesheet'>
<script src='https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js'></script>
<script src='https://cdn.jsdelivr.net/gh/fancyapps/fancybox@3.5.7/dist/jquery.fancybox.min.js'></script>
<script>
//<![CDATA[
    $('.post-body img').each(function() {
        var img_link = $(this).attr('src')
        if ($(this).parent('a') !== undefined) {
            $(this).parent('a').attr('data-fancybox', 'gallery');
        } else {
            $(this).wrap('<a href=' + img_link.replace(/(\/s\d+\/)/, '/s0/') + ' data-fancybox='gallery'></a>');
        }
    });
//]]>
</script>