Postman (400,9125) - Expected input credential was not present

[yudong_cai]

I followed the Two-Way SSL solution to test helloworld API on POSTMAN, and it worked fine.
I then added a new request in the same collection in postman to test https://sandbox.api.visa.com/vsps/search (ref Visa Stop Payment Service API Reference), but now I got this error - {"responseStatus":{"status":400,"code":"9125","severity":"ERROR","message":"Expected input credential was not present","info":""}}
I checked the request and response in Postman console, I can see Client Certificates are used, and this request header exists - Authorization: Basic VTVFRUVEM0k1SDJPUlFBVklSS1UyMWRBSnJrc29iT0xrSnVXakFRQWZhMXV6bENfZzoyWW8xTEJ4MU02MFo4MjNUd1c=
I didn't set the request header - clientId, because I don't know the clientId, and I think clientId is not require in sandbox.
Please help me to fix this issue.

[yudong_cai]

I've tested the foreign exchange API - https://sandbox.api.visa.com/forexrates/v2/foreignexchangerates, and I got the 200 response. Therefore, I feel the problem is with the VSPS endpoint server -  https://sandbox.api.visa.com/vsps/search