Purchase order & does not contain items for a stock transfer

What causes this issue?

The system did not find any item for a stock transfer in purchase order
&V1&.
Possible causes of error:
You have entered the wrong purchase order number.
The purchase order you have entered is not a stock transport order and
the item category of the purchase order items is not <LB>U</>.
The purchase order you have entered is not a standard purchase order for
cross-company-code stock transfers.
You can only post goods issues for stock transport orders belonging to
this order type in the Sales and Distribution system (SD). You cannot
enter the goods issue in Inventory Management.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Check whether your input is correct.
Check whether the purchase order is a stock transport order with item
type <LB>U</> or an inter-company-code stock transfer.
IF &DEVICE& = 'SCREEN'
<DS:TRAN.ME23N>Perform function</>
ENDIF
IF &[SWITCH]S4H_DOCU_ON_PREMISE& = 'X'.
If you have authorization, check in Customizing for Purchasing whether
goods issues for stock transport orders in the plant with this
purchasing document type are to be posted in the Shipping system or in
Inventory Management. If a delivery type has been entered in the
Customizing table, the goods issue takes place in the Shipping system.
In Customizing, choose:
Materials Management -> Purchasing -> Purchase Order -> Set Up Stock
Transport Order.
ENDIF.

Error message extract from SAP system. Copyright SAP SE.