S/4HANA SelfService Procurement - follow-on documents

Hello Experts,

I question regarding S/4 SSP (Self-Service Procurement). If a user uses the FIORI app "Employee Self Service", the user could create freetext or catalog based requisitions.

If the document is saved, my S/4 system creates a "purchase requisition".

As S/4 SSP should replace in most functionality SAP SRM (when not Ariba used), I'm expecting, that I could
influence the type of created follow-on document.

In SAP SRM you can customize and code by user-exit the type of relevant SRM shopping cart follow-on document:

* Purchase requisition
* Purchase order
* Reservation

Question: Is it possible in S/4 1909 on-premise to configure/customize the type of follow-on document OR

is S/4 in standard always creating a real "Banf" / BUS2105 "Purchase requisition" ?

I could not belive that, because the purchasing department does not like to handle purchase requisitions,
if the content of the PR is full qualified by catalog material...

If there is a configuration area to determine the follow-on document type, please give a tip, where this could be find (in IMG).

Thanks in advance