How to create an Catalog Task notification with necessary information.

Template:

sc_task.itil.role.custom.assignmentgroup
Task Details:

Short Description: ${short_description}

${mail_script:request_item_summary_task}

Task Description:
${description}

Click here to view Task:

${mail_script:custom_view_record_link}

Mail Script:

request_item_summary_task

var keys = [];
     var html = '<table style="height: 13px; width: 75%; border-collapse: collapse"; border="1"><tbody>';
     html = html + '<tr style="height: 13px;">';
    html = html + '<td style="width: 45%; height: 13px;"><strong>';
    html = html + 'Number:</strong></td>';
    html = html + '<td style="width: 30%; height: 13px;">';
    html = html + current.number + '</td></tr>';
    html = html + '<tr style="height: 13px;">';
    html = html + '<td style="width: 45%; height: 13px;"><strong>';
    html = html + 'Assignment group:</strong></td>';
    html = html + '<td style="width: 30%; height: 13px;">';
    html = html + current.assignment_group.getDisplayValue() + '</td></tr>';
    html = html + '<tr style="height: 13px;">';
    html = html + '<td style="width: 45%; height: 13px;"><strong>';
    html = html + 'Created By:</strong></td>';
    html = html + '<td style="width: 30%; height: 13px;">';
    html = html + current.opened_by.getDisplayValue() + '</td></tr>';
    html = html + '<tr style="height: 13px;">';
    html = html + '<td style="width: 45%; height: 13px;"><strong>';
    html = html + 'Date Created:</strong></td>';
    html = html + '<td style="width: 30%; height: 13px;">';
    html = html + current.opened_at.getDisplayValue() + '</td></tr>';
       var set = new GlideappVariablePoolQuestionSet();
    set.setRequestID(current.request_item);
    set.load();
    var vs = set.getFlatQuestions();
    for (var i = 0; i < vs.size(); i++) {
        if (vs.get(i).getLabel() != '' && vs.get(i).getDisplayValue() != '' && vs.get(i).getDisplayValue() != 'No') {
            html = html + '<tr style="height: 13px;">';
            var quest = vs.get(i).getLabel();
            html = html + '<td style="width: 45%; height: 13px;"><strong>';
            html = html + quest.replace("?", "") + ':</strong></td>';
            html = html + '<td style="width: 30%; height: 13px;">';
            if (vs.get(i).getDisplayValue() == 'true') {
                html = html + 'Yes' + '</td></tr>';
            } else if (vs.get(i).getDisplayValue() == 'false') {
                html = html + 'No' + '</td></tr>';
            } else {
                html = html + vs.get(i).getDisplayValue() + '</td></tr>';
            }
        }
    }
    html = html + '</table>';
    template.print(html);

custom_view_record_link:

(function runMailScript(/* GlideRecord */ current, /* TemplatePrinter */ template,
          /* Optional EmailOutbound */ email, /* Optional GlideRecord */ email_action,
          /* Optional GlideRecord */ event) {
           // Add your code here
 var html = '<table width="100%" border="0" cellspacing="0" cellpadding="0">  <tr>    <td width="25%">';
 var host = gs.getProperty('instance_name');
 var number = current.document_id.number;
   if(current.sys_class_name == 'incident'){
  html = html + "<a href='https://" + gs.getProperty('instance_name') +".service-now.com/nav_to.do?uri="+ current.sys_class_name + ".do%3Fsys_id=" + current.sys_id +"%26sysparm_stack=="+ current.sys_class_name +"_list.do%3Fsysparm_query=active=true' target='_blank' style='font-size: 16px; font-family: Helvetica, Arial, sans-serif; color: #ffffff; text-decoration: none; border-radius: 3px; background-color: #17a2b8; border-top: 12px solid #17a2b8; border-bottom: 12px solid #17a2b8; border-right: 18px solid #17a2b8; border-left: 18px solid #17a2b8; display: inline-block;'> "+ current.number +" </a></td></tr></table>";
 }
 else if(current.sys_class_name == 'change_request'){
  html = html + "<a href='https://" + gs.getProperty('instance_name') +".service-now.com/nav_to.do?uri="+ current.sys_class_name + ".do%3Fsys_id=" + current.sys_id +"%26sysparm_stack=="+ current.sys_class_name +"_list.do%3Fsysparm_query=active=true' target='_blank' style='font-size: 16px; font-family: Helvetica, Arial, sans-serif; color: #ffffff; text-decoration: none; border-radius: 3px; background-color: #17a2b8; border-top: 12px solid #17a2b8; border-bottom: 12px solid #17a2b8; border-right: 18px solid #17a2b8; border-left: 18px solid #17a2b8; display: inline-block;'> "+ current.number +" </a></td></tr></table>";
 }
 else if(current.sys_class_name == 'problem'){
  html = html + "<a href='https://" + gs.getProperty('instance_name') +".service-now.com/nav_to.do?uri="+ current.sys_class_name + ".do%3Fsys_id=" + current.sys_id +"%26sysparm_stack=="+ current.sys_class_name +"_list.do%3Fsysparm_query=active=true' target='_blank' style='font-size: 16px; font-family: Helvetica, Arial, sans-serif; color: #ffffff; text-decoration: none; border-radius: 3px; background-color: #17a2b8; border-top: 12px solid #17a2b8; border-bottom: 12px solid #17a2b8; border-right: 18px solid #17a2b8; border-left: 18px solid #17a2b8; display: inline-block;'> View Problem </a></td></tr></table>";
 }
 else if(current.sys_class_name == 'problem_task' || current.sys_class_name == 'change_task' || current.sys_class_name == 'sc_task' ){
  html = html + "<a href='https://" + gs.getProperty('instance_name') +".service-now.com/nav_to.do?uri="+ current.sys_class_name + ".do%3Fsys_id=" + current.sys_id +"%26sysparm_stack=="+ current.sys_class_name +"_list.do%3Fsysparm_query=active=true' target='_blank' style='font-size: 16px; font-family: Helvetica, Arial, sans-serif; color: #ffffff; text-decoration: none; border-radius: 3px; background-color: #17a2b8; border-top: 12px solid #17a2b8; border-bottom: 12px solid #17a2b8; border-right: 18px solid #17a2b8; border-left: 18px solid #17a2b8; display: inline-block;'> "+ current.number +" </a></td></tr></table>";
 }
 else{
  html = html + "<a href='https://" + gs.getProperty('instance_name') +".service-now.com/nav_to.do?uri="+ current.sys_class_name + ".do%3Fsys_id=" + current.sys_id +"%26sysparm_stack=="+ current.sys_class_name +"_list.do%3Fsysparm_query=active=true' target='_blank' style='font-size: 16px; font-family: Helvetica, Arial, sans-serif; color: #ffffff; text-decoration: none; border-radius: 3px; background-color: #17a2b8; border-top: 12px solid #17a2b8; border-bottom: 12px solid #17a2b8; border-right: 18px solid #17a2b8; border-left: 18px solid #17a2b8; display: inline-block;'> View Request </a></td></tr></table>";
 }
   template.print(html);
})(current, template, email, email_action, event);