Groovy script to notify agent when request is updated

Summary:

My groovy script is supposed to send a bell/email notification to agents when their request is updated but its not pushing anything through. Can you let me know if there is an issue with my script? I also set the trigger to 'AfterTrasactionPosted;

Content (please ensure you mask any confidential information):

def helpdeskSR = HRHelpDeskRequest;
def stripeCd = helpdeskSR?.StripeCd;
def srId = helpdeskSR?.SrId;

if (stripeCd == "ORA_SVC_HRHD") {
if (MessageTypeCd == 'ORA_SVC_CUSTOMER_ENTRY' || isAttributeChanged('Attachment')) {
try {
def recipientPartyId = helpdeskSR?.AssigneeResourceId;
def messageText;

        if (MessageTypeCd == 'ORA_SVC_CUSTOMER_ENTRY') {

            messageText = "A message was added for SR " + helpdeskSR?.SrNumber;

        } else if (isAttributeChanged('Attachment')) {