1) Please tick the indicator "Automatic purchase order" in the Vendor master record under Purchasing view.
2) SPRO --> Material Management --> External Service Management --> Source determination and default values --> For Purchase organization --> tick the indicator "Automatic PO generation for Service requisitions."
3) Create Service PR with multiple line items and assign the Vendor & purchase organization under the tab "Source of supply"
4) Call transaction ME59 --> Enter the purchase requisition number --> tick indicator "Per purchase requisition item" and then execute
The system will generate individual Service P.O per line item in the PR.