How to add Variables value in Notification ServiceNow?

Step 1:

Write mail script and add below code in Notification.

Name : variables_value_catalog_summary

template.print("Summary of Requested items:<br />");  
  var item = new GlideRecord("sc_req_item");
  item.addQuery("sys_id", current.sys_id);
  item.query();
  while(item.next()) {
      var keys = [];
      var set = new GlideappVariablePoolQuestionSet();	
      set.setRequestID(item.sys_id);
      set.load();
      var vs = set.getFlatQuestions();
      for (var i=0; i < vs.size(); i++) {
        if(vs.get(i).getDisplayValue() != '') {
           template.space(4);
           template.print('     ' +  vs.get(i).getLabel() + " = " + vs.get(i).getDisplayValue() + "<br />");  
        }
      }
  }

Step 2: Use below code in notification

${mail_script:variables_value_catalog_summary}