Alert configuration

Hello experts ,

I am currently working on alert configuration . I want to configure alerts for PO release .

The alert is working correctly,ie,  after every PO release we receive the email alert but the problem is that we can't populate/ fill container elements such as PO number .

I've checked the following discussions :

Alert - Container Filling

Alert container not working

Need to create custom alerts in SAP PI 7.4 single stack

Alerts in ECC

but i didn't find the way to populate the container elements .

Can you please help me so i can manage to populate the container elements without defining a workflow or using PI /XI system .

Thank you