Generate Purchase order automatically for OSP Work Orders

Hi gurus:

I am implementing Outside Processin. So I have created a new item for OSP, a new Ourside Processing Blanket Agreement, a Standard operation with an in-house (components) and supplier (OSP). After releasing the Work Order, the Supply Orchestration creates the Purchase Requisition but stuck 'In process' in purchasing, so the PO is not created. Do you know why?

Thanks in advance