OAuth 2 Client Credentials grant in ADFS - nordvall/TokenClient GitHub Wiki
This grant type is not supported in ADFS. Although Clients can be registered in ADFS, there are nowhere to register client secrets.
Example request:
POST /adfs/oauth2/token HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Host: xxx.yyy.zzz
Content-Length: 93
grant_type=client_credentials&resource=urn%3Apepsi%3Atest&client_id=MyClient&client_secret=abc
Response:
HTTP/1.1 400 Bad Request
Content-Type: application/json;charset=UTF-8
{"error":"unsupported_grant_type",
"error_description":"MSIS9611: The authorization server does not support the requested grant_type. The authorization server only supports 'authorization_code' or 'refresh_token' as the grant type."}
For more information, see OAuth 2 in ADFS.