3327501 - Error "unauthorized_client" returned while trying to obtain an access token to call the platform API methods for SAP BTP, Neo Environment.

You followed the procedure as described in Using Platform APIs to obtain an access token to call the platform API methods for SAP BTP, Neo Environment in Postman, and encountered error "unauthorized_client" as below:

"Image/data in this KBA is from SAP internal systems, sample data, or demo systems. Any resemblance to real data is purely coincidental."

SAP Business Technology Platform
Neo Environment

401, "unauthorized_client", "error": "unauthorized_client", Platform APIs, OAuth Client, OAuth Access Token, Post, /oauth2/apitoken/v1?grant_type=client_credentials , KBA , BC-NEO-SEC-IAM , Authentication, Authorization(Cloud Platform Neo) , Known Error