Controle source type when raising a requisition

Summary

Controle source type when raising a requisition

Content

Hello experts

Have few questions:

1. Shop by Category: when creating a requisition through shop by category; the source agreement is BPA because the item is part of a BPA-; is there a possibility to order from inventory using shop by category option? or is this option only made to create a requisition with a supplier?
2. Is there a way to control who can change the source type (Inventory or Supplier) ?
   • Via "Enter Requisition line"- source type is defaulted to "Supplier" it is only when you enter an item that is "internally orderable" that the source type changes to 'Inventory"- is it possible to controle which user can change the source type ? our case is that if an item is internally orderable it should always be sourced internally and only few people can order to a supplier (outside)?