User account for requestor

Hello All,

I would like to understand do we need to create every requester in oracle with user account? Or employee record alone is enough?

Use case: Preparer will create request for all the requestors with the requestors name and approval should route through requestors supervisor. If requestor doesn't have a user account in oracle will the approval flow through? or do we need to create the requestor in oracle user account?

Thanks in advance