Correct Answe r: The client ID and secret obtained from Anypoint Exchange for the API instance in the STAGING environment
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>> We CANNOT use the client ID and secret of Anypoint Platform account or any individual environments for accessing the APIs
>> As the type of policy that is enforced on the API in question is "Client ID Enforcment Policy", OAuth token based access won't work.
Right way to access the API is to use the client ID and secret obtained from Anypoint Exchange for the API instance in a particular environment we want to work on.
Reference:
Managing API instance Contracts on API Manager
https://docs.mulesoft.com/api-manager/1.x/request-access-to-api-task
https://docs.mulesoft.com/exchange/to-request-access
https://docs.mulesoft.com/api-manager/2.x/policy-mule3-client-id-based-policies