How to set up payment authorization in AP

Are AP payment processing privileges separated from invoicing privileges? Also, are these privileges (payment processing and invoicing) granted on a per-user basis, or are they restricted on a per-business-unit basis?

What I would like to achieve:

I would like to clarify the classification of the authority for invoicing and payment processing, which are operations related to AP. Also, I would like to deepen my understanding of the workflow and how it relates to internal controls.

I would appreciate it if you could tell me about the above question. Thank you!