PR/PO Flexible Workflow with role Assignment

Dear SAP Expert,

I person a request to adhd user's manager to the support workflow without utilizing the HR module (it's not included successful the project).

I tried to grip the request utilizing SAP Flexible workflow for PR/PO and one didn't recognize however to nexus the relation to the idiosyncratic manager (i'm connected the Manage workflow for Purchase requisitions app)

Client doesn't person HR module activated. Do one request to person HR module activated oregon is determination immoderate different modular solution ?