No ABAP PSS port has been entered for reference ship-to party &

What causes this issue?

No ABAP PSS port has been maintained for the selected reference ship-to
party.

System Response

If you are using the IDoc Copy Management tool, a PSS port must be
assigned to every reference ship-to party in the partner profile using
the standard function module WDL_COPY_LOG.
The IDoc Copy Management tool functions in a way that IDoc-creating
applications create and output IDocs for reference stores. The port must
also be assigned to these references. This way, the outbound IDocs are
logged for the tool and can be copied via transaction WDL_COPY_FILL to
the targets (ship-to parties) that are maintained in the system.

How to fix this error?

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

You have to maintain a PSS port for the selected ship-to party in the
partner profile for the corresponding message type. You need to create
a PSS port using the function module WDL_COPY_LOG in the partner
profile. You then select this as a port for the reference in the partner
profile.

Error message extract from SAP system. Copyright SAP SE.