How to write BPM rule to send approval to single user for breakdown maintenance WO

We have a requirement where the breakdown maintenance WO need to be approved before being sent to 3rd Party service provided (OSP Maintenance).

We are using E Signature and E Records for WO approval since OOTB approval process is not available in Maintenance Management.

After completing all configurations, the WOs are going into Pending Approval status.

But no bell notifications or email are getting sent to approver.

Would appreciate any help on the BPM rules to fix the issue. Attached screenshot captures the rule written.