Link to test case:
Debugger code (debug.datatables.net):
Error messages shown:
Description of problem:

here instead of the view course we need to add the number of counted courses

were using this code for download or export file

echo ' <script type="text/javascript" language="javascript" src="https://cdn.datatables.net/1.11.3/js/jquery.dataTables.min.js"></script>';
echo ' <link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/select/1.3.3/css/select.dataTables.min.css">
<link rel="stylesheet" type="text/css" href="https://cdn.datatables.net/buttons/2.0.0/css/buttons.dataTables.min.css">
<script type="text/javascript" language="javascript" src="https://cdn.datatables.net/buttons/2.0.0/js/dataTables.buttons.min.js"></script>
<script type="text/javascript" language="javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jszip/3.1.3/jszip.min.js"></script>
<script type="text/javascript" language="javascript" src="https://cdnjs.cloudflare.com/ajax/libs/pdfmake/0.1.53/pdfmake.min.js"></script>
<script type="text/javascript" language="javascript" src="https://cdnjs.cloudflare.com/ajax/libs/pdfmake/0.1.53/vfs_fonts.js"></script>
<script type="text/javascript" language="javascript" src="https://cdn.datatables.net/buttons/2.0.0/js/buttons.html5.min.js"></script>
<script type="text/javascript" language="javascript" src="https://cdn.datatables.net/buttons/2.0.0/js/buttons.print.min.js"></script>';
echo "
<script>
$(document).ready(function() {
        $('.generaltable').DataTable({
                dom: 'Bfrtip',
                pageLength: 30,
                 lengthMenu: [[10, 20, 50, 100,-1], [10,20, 50, 100, 'Todos']],
        buttons: [
            {
                extend: 'collection',
                text: 'Export',
                buttons: [
                    'copy',
                    'excel',
                    'csv',
                    'pdf',
                    'print'
                ]
            }
        ]})
        
    } );</script>";

Edited by Colin - Syntax highlighting. Details on how to highlight code using markdown can be found in this guide.