I am unable to get a good response, and having hard time finding Docs. Can't find a way to lookup the inner error code at all either. I get a token using curl -L -X POST 'https://login.microsoftonline.com/51bcb6e4-b738-4e87-a795-768e3f13b94f/oauth2/v2.0/token' \ -H 'Content-Type: application/x-www-form-urlencoded' \ --data-urlencode 'client_id=5bbd5786-31d3-4d84-a8d0-a0dac6522f93' \ --data-urlencode 'scope=https://graph.microsoft.com/.default' \ --data-urlencode 'client_secret=<secret>' \ --data-urlencode 'grant_type=client_credentials' and then take the access_token value, and do this curl -L -X GET 'https://graph.microsoft.com/v1.0/teams/d89133ea-bf32-4957-8300-aa5e083f45c1/channels/19:5b075a993aee4b3fa8f23be2cbb3b514@thread.skype/messages' \ -H 'Authorization: Bearer <token value from above>' But I get this error 403: { "error": { "code": "UnknownError", "message": "", "innerError": { "date": "2021-03-09T19:15:23", "request-id": "c9a8cf3a-b914-44a8-a66a-506634f09d77", "client-request-id": "c9a8cf3a-b914-44a8-a66a-506634f09d77" } } } how can I troubleshoot? the url for the GET seems right, based on all my research. we are using resource specific consent permissions, but the app is installed in the channel that I am trying to list messages. from