Cannot retrieve data from Active Directory

Question

I created a new Blazor application with Azure AD authentication. Login functionality works as expected. Now I need to retrieve a list of users of a particular group. On Azure AD, I created a Client Secret. Also, I added Microsoft.Graph permissions Directory.Read.All, Group.Read.All, and GroupMember.Read.All, and granted admin consent for the permissions.

Here are the permissions:

Here is my code I use to retrieve the users of a group:

            var scopes = new string[] { "https://graph.microsoft.com/.default" };
        var confidentialClient = ConfidentialClientApplicationBuilder
            .Create(_adSettings.ClientId)
            .WithAuthority($"{_adSettings.Instance}/{_adSettings.TenantId}/ v2.0")
            .WithClientSecret(_adSettings.ClientSecret)
            .Build();

        GraphServiceClient graphServiceClient = new GraphServiceClient(new DelegateAuthenticationProvider(async (requestMessage) => {
            // Retrieve an access token for Microsoft Graph (gets a fresh token if needed).
            var authResult = await confidentialClient.AcquireTokenForClient(scopes).ExecuteAsync();

            // Add the access token in the Authorization header of the API
            requestMessage.Headers.Authorization =
            new AuthenticationHeaderValue("Bearer", authResult.AccessToken);
        }));

            var members = await graphServiceClient.Groups["mygroup@mydomain.com"]
                .Members
                .Request()
                .GetAsync();

The last statement throws an exception:

An error occurred sending the request. HttpStatusCode: 404: NotFound

I tried to replace it with

var users = await graphServiceClient.Users.Request().GetAsync();

But result was the same.

Answer 1

You should specify your group object ID instead of the group name:

My test group:

Test code and result:

UPDATE:

This is a C# console app code for this test, hope it helps :

using Microsoft.Graph;
using Microsoft.Graph.Auth;
using Microsoft.Identity.Client;
using System;



namespace graphsdktest
{
    class Program
    {
        static void Main(string[] args)
        {

            var clientId = "<Azure AD App ID>";
            var clientSecret = "<App secret>";
            var tenantID = "<tenant ID>";
            IConfidentialClientApplication confidentialClientApplication = ConfidentialClientApplicationBuilder
                .Create(clientId)
                .WithTenantId(tenantID)
                .WithClientSecret(clientSecret)
                .Build();

            ClientCredentialProvider authenticationProvider = new ClientCredentialProvider(confidentialClientApplication);

            var graphClient = new GraphServiceClient(authenticationProvider);

            var result = graphClient.Groups["<group ID>"].Members.Request().GetAsync().GetAwaiter().GetResult();

            foreach (var user in result) {
                Console.WriteLine(user.Id);
            }

        }
    }

}

UPDATE 2:

If you get some permission exception while you query members of a group, pls go to Azure AD => App registrations => find your app => API permissions => Add a permission => Microsoft graph api => application permission => GroupMember.Read.All :

And click This button to finish the grant process :