Transaction for output POs to SUS

Hi experts

I am implementing EBP-SUS in a single client and required XI configurations, but when I try to send Po to SUS and error occur SLD NOT ASSIGNED TO LOGICAL SYSTEM, but it's done in define backend system.

I would like to know if there is a transaction in abap that I can send this PO to SUS so I can debug and see why my Sld it's not been found, is transaction not exist , what is the service in sicf where can I put a parameter to debug it?

Thanks

Nilson