Discussion feature not visible in My Activities

We have a customer who are implementing the Progress app. The big stumbling block is when the user records progress they would like the ability to add a commentary about the progress of the activity. In the OPC Documentation it refers to the discussion feature being exactly what we are looking for.

However, we can't see this in the My Activities view.

I found this link which is the ‘OPC Progress User Guide’ doc… and the last section is entitled ‘Add a Discussion’.

https://docs.oracle.com/cd/E80480_01/English/user_guides/progress_user_guide/154401.htm#t154401

In the ‘tips’ section at the bottom (images attached) it indicates you can turn the ‘discussions’ icon on or off within the ‘columns’ Settings. However, this option is not available in the ‘Settings’ for the list view of ‘My Activities’.