SAP IS-U -> PI -> C4C Integration issue

Dear Experts,

I need your help.

Our company is implementing SAP IS-U with C4C via SAP PI, but we are facing a problem. I think that the "Communication channel" is working fine, but when an IDoc is being sent from ERP in C4C side we are receiving the following message:

Basically Z001 refers to ERP customer account groups. Please check the mapping from PI (2)

(1)

(2)

Would you be able to help us?

Regards