Graph API throws error - "cannot be used like a method"

I have a code that was used from: https://github.com/microsoft/AzureProvisioningUsingFunctions/tree/main

  var getAllMessages = await graphClient.Users[UserPrincipalName].Chats
 .GetAllMessages()
 .GetAsync();

It shows a compiler error:

Non-invocable member 'ChatsRequestBuilder.GetAllMessages' cannot be used like a method. AzureProvisioning C:\Deeku\Personal\work\usermanagement\Code\AzureProvisioning.cs 728 Active

In addition to this, I have a code that is also not working:

  var signIns = await graphClient
    .AuditLogs
    .SignIns.GetAsync((requestConfiguration) =>
       { 
        requestConfiguration.QueryParameters.Filter = "UserPrincipalName eq '{UserPrincipalName}'  and isInteractive eq true and status/errorCode eq 0"; 
        requestConfiguration.QueryParameters.Orderby = new string[] { "createdDateTime" 
   }; 
 });
 var signInsD = signIns.Distinct();

The error:

'SignInCollectionResponse' does not contain a definition for 'Distinct' and no accessible extension method 'Distinct' accepting a first argument of type 'SignInCollectionResponse' could be found (are you missing a using directive or an assembly reference?) AzureProvisioning

To getAllMessages, modify the code like below:

var result = await graphClient.Users["{user-id}"].Chats.GetAllMessages.GetAsGetAllMessagesGetResponseAsync((requestConfiguration) => { requestConfiguration.QueryParameters.Top = 2; });

Refer this MsDoc

The error is because you are trying to use the Distinct method on the SignInCollectionResponse object.

• The Distinct method is not available directly on this type because it is not a collection type but a response object that contains a collection.

Hence as a workaround modify the code like below:

namespace GraphApiExample
{
    class Program
    {
        static async Task Main(string[] args)
        {
            var clientId = "ClientID";
            var tenantId = "TenantID";
            var clientSecret = "Secret";

            var clientSecretCredential = new ClientSecretCredential(tenantId, clientId, clientSecret);
            var graphClient = new GraphServiceClient(clientSecretCredential);

            var userPrincipalName = "rukuser@xxx.onmicrosoft.com";

            var result = await graphClient.AuditLogs.SignIns.GetAsync((requestConfiguration) =>
            {
                requestConfiguration.QueryParameters.Filter = $"UserPrincipalName eq '{userPrincipalName}' and isInteractive eq true and status/errorCode eq 0";
                requestConfiguration.QueryParameters.Orderby = new string[] { "createdDateTime" };
            });

            if (result?.Value != null)
            {
                
                var signInsList = result.Value.ToList();

                // Apply Distinct based on some criteria, for example, by Id
                var distinctSignIns = signInsList
                    .GroupBy(s => s.Id)  // Group by Id
                    .Select(g => g.First())  // Select the first entry from each group
                    .ToList();

                foreach (var signIn in distinctSignIns)
                {
                    Console.WriteLine($"Sign-in ID: {signIn.Id}, UPN: {signIn.UserPrincipalName}, Date: {signIn.CreatedDateTime}");
                }
            }
            else
            {
                Console.WriteLine("No sign-ins found.");
            }
        }
    }
}

Reference: List signIns - Microsoft Graph v1.0 | Microsoft