404 error while creating Online Meeting using microsoft graph api c# without login into AzureActiveDirectory

Question

I am trying to create Online Meeting using microsoft graph api without login into AzureActiveDirectory with asp.net web application.For this my app has below permissions which are required as per documentation https://docs.microsoft.com/en-us/graph/api/application-post-onlinemeetings?view=graph-rest-1.0&tabs=csharp with client credential auth flow https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-client-creds-grant-flow without immediate interaction with a user.I am able to retrive access token successfully as per client-creds-grant-flow. I tried Micosoft.Graph and Micosoft.Graph.Beta still getting 404 error.

Create online meeting code

  var graphClient = GetAuthenticatedClientCredential();
            var onlineMeeting = new OnlineMeeting
            {
                StartDateTime = DateTimeOffset.Parse("2020-10-01T10:30:34.2444915+00:00"),
                EndDateTime = DateTimeOffset.Parse("2020-10-01T11:00:34.2464912+00:00"),
                Subject = "Create Online Meeting-Without user login to Office 365"
            };

            return await graphClient.Me.OnlineMeetings
                 .Request()
                 .AddAsync(onlineMeeting);

Access Token code

 public static async Task<string> GetUserAccessTokenAsyncByCc()
        {
            IConfidentialClientApplication cca = ConfidentialClientApplicationBuilder.Create(appId)
               .WithTenantId(appTenantId)
               .WithClientSecret(appSecret)
               .Build(); 
            
             string[] scopes1 = new string[] { "https://graph.microsoft.com/.default" };
            //string[] scopes1 = new string[] { "https://graph.microsoft.com/OnlineMeetings.ReadWrite.All" };
            // string[] scopes1 = new string[] { "https://graph.microsoft.com/beta/OnlineMeetings.Read.All" };
            //string[] scopes1 = new string[] { "https://graph.microsoft.com/beta/.default" };
            var result = await cca.AcquireTokenForClient(scopes1).ExecuteAsync();
           
            return result.AccessToken;
        }

and Auth Provider code

public static GraphServiceClient GetAuthenticatedClientCredential()
        {

            DelegateAuthenticationProvider provider = new DelegateAuthenticationProvider(
                     async (requestMessage) =>
                     {
                         string accessToken = await GetUserAccessTokenAsyncByCc();
                         requestMessage.Headers.Authorization = new AuthenticationHeaderValue("bearer", accessToken);
                     });

            GraphServiceClient graphClient = new GraphServiceClient(provider);

            return graphClient;


        }

app permission image below are the necessary app permission

Carl Zhao Carl Zhao · Accepted Answer · 2020-09-24T09:52:28

You can only use delegated permissions to create an onlineMeeting, so you must log in as a user, and you cannot use the client credential flow. You need to use the auth code flow to obtain the token.

404 error while creating Online Meeting using microsoft graph api c# without login into AzureActiveDirectory

1 Answers