private static async Task CreateGroup(string jsonGroup)
        {
            AuthenticationConfig config = AuthenticationConfig.ReadFromJsonFile("appsettings.json");


            Debug.WriteLine("===================== Create Alvianda group: =======================");

            try
            {
                var httpClient = new HttpClient();
                var apiCaller  = new ProtectedApiCallHelper(httpClient);
                await apiCaller.PostWebApiAndProcessResultASync($"{config.ApiUrl}v1.0/groups",
                                                                jsonGroup,
                                                                Program.AuthenticationResult.AccessToken,
                                                                Display);
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.Message);
            }
            finally
            {
                Debug.WriteLine("========================= End list ==========================================");
            }
        }
        private static async Task <bool> AddGroupMember(string grpName, string userName)
        {
            try
            {
                // get object id for userPrincipalName
                var userObjectId = GetUserObjectId(userName).GetAwaiter().GetResult();

                // get object id fro group name
                var groupObjectId = GetGroupObjectId(grpName).GetAwaiter().GetResult();

                AuthenticationConfig config = AuthenticationConfig.ReadFromJsonFile("appsettings.json");

                // call MS Graph Api function that attaches a member to the group
                var httpClient = new HttpClient();
                var apiCaller  = new ProtectedApiCallHelper(httpClient);
                var payloadUrl = "{'@odata.id': 'https://graph.microsoft.com/v1.0/directoryObjects/" + userObjectId + "'}";
                await apiCaller.PostWebApiAndProcessResultASync($"{config.ApiUrl}v1.0/groups/{groupObjectId}/members/$ref",
                                                                payloadUrl,
                                                                Program.AuthenticationResult.AccessToken, null);

                return(true);
            }
            catch (Exception ex)
            {
                return(false);
            }
        }