Error: cURL to get OAuth Token

Summary

Client authorization failed: cURL to get OAuth Token

Content

I configured confidential App in IDCS with client & resource (attached please refer to the screenshots). When I use cURL to get the OAuth token, I got error "Client authorization failed" like below. Any idea what configuration I need to check in IDCS?

cURL command

C:\curl\curl-7.69.1-win64-mingw\bin>curl -H "Authorization: Basic ZDczZDE1ODFkMTQwNDUyZjhlNzlmMDAzNjcyMDk3MTE6NDFiMTU5YTYtZTQxMy00MjJhLWE4ZDQtODY4NjFlNjczOGQ2" -H "Content-Type: application/x-www-form-urlencoded;charset=UTF-8" --request POST https://idcs***.identity.oraclecloud.com/oauth2/v1/token -d "grant_type=client_credentials&scope=urn:opc:idm:__myscopes__"

Response
{"error":"unauthorized_client","error_description":"Client authorization failed"}