Delete groups in Microsoft Graph API in C# - azure-active-directory

Question

I get an authorization 401 error code when I try to delete a Group from the API in C# but if I try it in postman it succeeds. Feels kinda weird because I run the same command but it doesn't work...
The problem I think I have is that to DELETE a group in Office 365 I need to login to my account and that the application can't makes this action.
I gave all Group.ReadWrite.All access and all other permissions for the application. So I think I need to pass my Login credentials for Azure AD or am I incorrect.
Request :
StatusCode: 401,
ReasonPhrase: 'Unauthorized',
Version: 1.1,
Content: System.Net.Http.NoWriteNoSeekStreamContent,
Headers:
EDIT
I tried to not use my GetAccessToken() and use the token I got when using OAUTH 2.0 verification in Postman. If I took that bearer token I had no problem running my script and using DELETE.
So my question what the difference of using ADAL in C# code and the call that Postman Auth2.0. When using Postman I get a login page where I login to my Azure account, can I replicate this in code? For the authentication in C# I use this example.
NEW EDIT
As one wrote in the chat, I checked the access token and what roles I had on a website.
roles: [
"EduRoster.Read.All",
"Mail.ReadWrite",
"User.ReadWrite.All",
"Calendars.Read",
"People.Read.All",
"Group.Read.All",
"Directory.ReadWrite.All",
"MailboxSettings.Read",
"Contacts.ReadWrite",
"Group.ReadWrite.All",
"Notes.Read.All",
"Directory.Read.All",
"User.Read.All",
"Mail.Read",
"Calendars.ReadWrite",
"Mail.Send",
"MailboxSettings.ReadWrite",
"Contacts.Read",
"Member.Read.Hidden",
"Notes.ReadWrite.All"]

Answer 1

Some clarification: If you have a token and it doesn't have the necessary claims/permissions to make the API call you are trying, you'll should get a 403 Forbidden. If the token is missing in the API request or malformed, you'll get a 401 Unauthorized. Please see https://developer.microsoft.com/en-us/graph/docs/concepts/errors.
Are you making direct HTTP REST calls to Graph, or are you using the client library? I suggest that you look at some of our samples to get started for examples of token acquisition together with calls to Microsoft Graph. Try https://github.com/microsoftgraph/console-csharp-snippets-sample (uses a .Net client library) or https://github.com/microsoftgraph/aspnet-connect-rest-sample (uses direct HTTP REST calls).
Also are you acquiring a token in the context of a (signed-in) user, or in the context of the application (no signed in user)? If the former, you need to request a "delegated" permission. If the latter, you need to request an "application" permission. Please see these concepts: https://developer.microsoft.com/en-us/graph/docs/concepts/auth_v2_user and https://developer.microsoft.com/en-us/graph/docs/concepts/auth_v2_service
Hope this helps,

Answer 2

You're on the right track.
The Delete Group method support both Delegated (Authorization Code or Implicit OAUTH grants) and Application (Client Credentials OAUTH grant) models. Both Delegated and Application flows require the Group.ReadWrite.All scope.
The reason you're getting a 401 Unauthorized error is that your application hasn't received Admin Consent for the tenant you're connected too. When using Client Credentials there is no User to authenticate so before your application can interact with the tenant, an Admin must first explicitly authorize your application and the scopes you're requesting.
You can find a walk through at v2 Endpoint and Admin Consent.