S/4HANA - Flexible Workflow - Exception Handling - How to configure activity as required action?

Hi,

We've created a custom flexible workflow. In Manage Workflows Fiori App, we want to configure required action in exception handling section of workflow step. We have defined activities in flexible block but not able to see them in required action drop down. Our query is technically how to make a flexible block activity into an exception handling activity and bring it into the exception handling required action drop down.

For e.g. for scenario workflow - WS00800208 - Change Record Discrete Industry, while adding action to exception handling, we can see activities as shown below. Similarly we also want to bring our own custom activities in exception handling.

Thanks & Regards

Mohit