Creating a custom alert message template

Summary

Variables for creating a custom alert message template to the Learner

Content

I am trying to create a custom alert template to send a message to the learner when the Learning Specialist enols him in an Offering.

The ‘Custom Alert payload’ variables do not include enough variables to make the message more meaningful, for example activity dates, times, classroom etc. (Oracle Fusion Learning Cloud: Create Custom Alert's for Learning? (Doc ID 2459472.1)

I tried to use the ‘Activity Definition Changed for instructor Payload’ and  ‘Offering Definition Change Payload’ variables but they are all returned as ‘null’ in the alert message