use graphAPI to send message by application

[lobbs]

I created a AAD tenant for my user.

And I use the client-credentials-provider to pass through the authorization.

But when I tried to call the send messgae API it showed the error message below.

409Graph service exception Error code: Unauthorized

 409Error message: Message POST is allowed in application-only context only for import purposes. Refer to https://docs.microsoft.com/microsoftteams/platform/graph-api/import-messages/import-external-message... for more details.

I am wondering whether its unavailable to send messgae through client-credentials-provider ?

Because I wanna send the message by my application without oauth2.0 follow, is there any way to realize that?

[#2]

We are looking into this, we will get back to you.

[#3]

@lobbs - Could you please confirm the below asks?

1. Please let us know in which step you are seeing the error.
2.  Please confirm if you are using Application permissions or Delegated permissions?

[#4]

@Meghana-MSFT 

1. Please let us know in which step you are seeing the error.

->When I execute my code to call the send message API 

1.  Please confirm if you are using Application permissions or Delegated permissions?

->Yes,I am using the application permissions

By the way , as I confirmed with the other guys, they said the send channel message API only could be used by content import mode..so which means it is not supportted for normal use .

[#5]

@lobbs - We tried https://docs.microsoft.com/en-us/microsoftteams/platform/graph-api/import-messages/import-external-m... example and our API call was successful. 

Please check this document Send chatMessage in a channel or a chat - Microsoft Graph v1.0 | Microsoft Docs, if you want to send messages to a normal channel.

Could you please confirm what do you mean by client-credentials-provider?