Inbound delivery not defined in confirmation control key

What causes this issue?

The confirmation control key entered in the purchase order or in
scheduling agreement &V1&, item &V2&, does not include a confirmation
category corresponding to the internal category '2' (shipping
notification/inbound delivery).

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?

Change the confirmation control key in the PO or scheduling agreement.
(Note that it cannot be changed if a goods receipt has already been
posted).
<DS:TRAN.ME22N>Change Purchase Order</> or
<DS:TRAN.ME32L>Change Scheduling Agreement</>.
INCLUDE NA_SYSADMIN1 LANGUAGE EN


&WHAT_TO_DO& (system administrator)
If necessary, maintain the confirmation control facility.

Error message extract from SAP system. Copyright SAP SE.