Custom alert for voluntary assignments

Summary:

Could someone help me create these custom alerts:

1. All Team Voluntary Assignments Approaching 30 Days - Group by Manager
   1. This worklist notification would go to line managers 25 days after assignment date for all voluntary assignments for their direct reports.
   2. I need html for the message body as well.
2. All Voluntary Assignments Assigned Since Last Run - Group by Learner
   1. I followed the instructions outlined in the Oracle document:
   2. Document 2786113.1
   3. The since last run expression doesn't work for me: exists (SELECT 'x' from dual where ${assignmentCreatedDate} >= (select nvl(max(runs.run_end),sysdate-1) from hrc_alert_runs runs, hrc_alerts_b alerts where runs.alert_id = alerts.alert_id and alerts.alert_code = 'PUT_ALERT_CODE_HERE'