Embedded image in email not showed in Teams channel

@Huynh, Phong - Are you developing any Teams app? If yes, could you please share the steps on how you are sending the image in the Teams channel?

Huynh, Phong - Are you developing any Teams app? If yes, could you please share the steps on how you are sending the image in the Teams channel?

I have a C# registered app that is currently perform a few tasks on Users object using Graph API. I wanted to extend the app functionalities to send messages with attached images to a Teams channel. The first problem that I ran into was that, by design, messages cannot be sent to Teams channel under application context. User authentication and interactive user consent are required. I try to sign in a service account with user name and password and attempt to send the chats:

var scopes = new[] { "User.Read", "Chat.ReadWrite" };

var options = new UsernamePasswordCredentialOptions

{

AuthorityHost = AzureAuthorityHosts.AzurePublicCloud,

};

var userNamePasswordCredential = new UsernamePasswordCredential("Username", "password", "My tenant ID", "My client ID", options);

var graphClient = new GraphServiceClient(userNamePasswordCredential, scopes);

var chatMessage = new ChatMessage { Body = new ItemBody { Content = "Test"}};

var chat = graphClient.Teams["My Teams ID"].Channels["My channel ID"].Messages.PostAsync(chatMessage).Result;

I'm getting below error message:

Exception: "AuthenticationFailedException: UsernamePasswordCredential authentication failed: AADSTS65001: The user or administrator has not consented to use the application with ID 'My App ID' named 'My App Name'. Send an interactive authorization request for this user and resource."

I have not been able to figure out how to do that so I gave up and use a work around by simply sending emails with attached images using SMTP to the Teams channel's email address. That works and the email text is displayed in channel. However, the attached image is only showed as place holder as I described in the post.

@Huynh, Phong - Could you please verify that an administrator has granted consent for the required permissions (User.Read, Chat.ReadWrite) for your application. This can be done through the Azure portal.