403 Forbidden - Submit a requisition processing request header - REST API

Summary:

Hi we are trying create a purchase order using a REST API.
I checked the documentation and dont have API to create a new purchase order, but have a API to process the requistion to purchase order.

Submit a requisition processing request header -
But we are receiving 403 forbidden.

If i try Get all requisition processing request headers ( ) still showing the same message.

But if i try check all requisitions in system its possible to see.
Have specific role to use this API ?

I found in forum this roles :

1) Add the privileges:

Manage Purchase Order by Web Service

(PO_MANAGE_PURCHASE_ORDER_WEB_SERVICE_PRIV)