Closed email/ bell notification is not working

Summary:

Content (please ensure you mask any confidential information):

I created a groovy script I can use to notify the primary contact for when the request is closed in HR Help Desk? I have used the following script below but its not working. I am also using the BeforeUpdate trigger.

.

• TRIGGER TYPE: Before Update in Database
• OBJECT: HR Help Desk Request
• Use Case: Send a notification to the primary contact when an SR has been closed.
• Note: You can override the Notification Text and Recipients using the Notification Preferences page.
  */

if (isAttributeChanged('StatusCd') && StatusCd == 'ORA_SVC_HRHD_CLOSED') {
try {
def recipientPartyId = PrimaryContactPartyId