OCI gen3 rest api for start/ stop OIC service

Summary:

We are trying to execute Start/Stop service via rest api following documentation from oracle

and API available to invoke Oracle integration API. Tried to follow multiple blogs available to create correct authentication method to execute this API but getting error

"

{    "code": "NotAuthenticated",    "message": "The required information to complete authentication was not provided or was incorrect."}

"
even when I able to execute Get OCI announcements api using same API authentication key. Reference blog

https://ashi-k-singh.medium.com/invoking-oci-rest-apis-using-postman-3fda258b0f7a

Also tried to configure application using steps mentioned in https://www.ateam-oracle.com/post/identity-cloud-services-oauth-20-and-rest-api blog but still getting same error.