SM to SMAX Case exchange


I am trying to configure Incident CaseExchange between Service Manager & Service Management by following the document and stuck at the below error. (Bi-Directional caseExchange)

1. Created & Configured External System in SMAX.

2. Created and Configured CaseExchange Integration Instance and it getting triggered. (Connection is successful to SMAX)

3. Once Incident is created in SM, an Integration Instance task is getting triggered and failing to process with the error "Error calling method: doHttpRequest Exception (java.lang.Exception: Return Code: 401)"

I verified credentials on both sides (OPB & SM) and it is correct. SM Log shows only above mentioned error.

Kindly suggest how to troubleshoot further.