Which roles/privileges are needed for Responsive Self Service Procurement?

Hello,

We are trying to test the new Responsive Self Service Procurement (RSSP) app in our DEV environment, but are struggling to figure out how to set security to enable access, using our existing custom PO Requester role.

First, we already have a custom PO Requester role, that has the Manage Requisition role assigned. However, when we try to access the new RSSP application, we get an error stating "You aren't assigned to a business unit that supports requisitioning". That is not true, as we are all assigned to our main BU and it has Procurement enabled.

Next, we tried adding the "Requisition Self Service Responsive Application User" role to our custom PO Requester role. This gave the same results as above.