//sails backend makes a call to this function

download: function( req, res){

        var page = req.param("draw");
        var columns = req.param("columns");
        var searchChars = req.param("search").value;
        var where = (searchChars ===''?{}:{ email : { 'contains' : searchChars } });
        User.count({}, function (err, count) {
            
            User.find(where).then (function (users) {
        
        return res.end(JSON.stringify({ data: users }));
      });

        });
    }
};

//front end

var user_table = $('#datatable').dataTable({
        "columnDefs": [ { "searchable": true, "targets": 3 }],
        "processing": true,
        "ordering": false,
        "bFilter": true,
        "scrollX": false,
        "ajax": "/users/explore",
        "serverSide": true,
        "columns": customColumns,
        dom: "Bifpl",
        "buttons": [
                                        {
                        
                                        text: 'Export All to Excel',
                                        action: function (e, dt, button, config){
                                            
                                            $.ajax({
                                                        "url": "/users/download",
                                                        "data": dt.ajax.params(),
                                                    
                                                        "success": function(res, status, xhr) {
                                                            res = JSON.parse(res).data;
                                                            var csvData = new Blob([res], {type: 'text/csv;charset=utf-8;'});
                                                            var csvURL = window.URL.createObjectURL(csvData);
                                                            var tempLink = document.createElement('a');
                                                            tempLink.href = csvURL;
                                                            tempLink.setAttribute('download', 'listOfUsers.csv');
                                                            tempLink.click();
                                                        }
                                            });
                                        }//end action
                                    }//end buttons
                    ]
    });

    
});

The produced csv shows objects and does not show columns with new headers in them