ISSUE
I am using IBM API Connect as a gateway where I don't have the control over internal authorization server. Due to this if any request fails due to the authorization issue, then it throws an error in the below format:
{
"httpCode": "401",
"httpMessage": "Unauthorized",
"moreInformation": "Invalid client id or secret."
}

Whereas expected CAMARA format is:
{
"status": 401,
"code": "UNAUTHENTICATED",
"message": "Request not authenticated due to missing, invalid, or expired credentials."
}

In this case the request gets rejected at the server level itself and it doesn't reach till my code to handle it. Due this I am unable to change the response format.

Currently, I am working with GSMA to close the certification for Sim Swap service but due to this particular use case it is not done.
My suggestion is to ignore this use case for certification as I am sure other MNO's will also face this limitation.