How to use modern authentication to execute EXO V2 PowerShell commands through program in Asp.NET Core C#

Question

We have register an application with permission Delegated permission: Exchange.Manage, Application permission: Exchange.ManageAsApp

When try to open Runspace using that token to execute Remote EXO V2 command but with that system returns error: Connecting to remote server outlook.office365.com failed with the following error message : For more information, see the about_Remote_Troubleshooting Help topic.

We use below code to connect:

   PSCredential pSCredential = new PSCredential(inputUserName, new NetworkCredential("", inputPassword).SecurePassword);                   
     
   string MailboxName = pSCredential.UserName;                   
     
   string scope = "https://outlook.office365.com/.default";   
     
   string ClientId = Configuration.Client_Id;                  
     
   string clientSecret = Configuration.ClientSecret;        
     
                 
     
   HttpClient Client = new HttpClient();                   
     
   var TenantId = ((dynamic)JsonConvert.DeserializeObject(Client.GetAsync("https://login.microsoftonline.com/" + MailboxName.Split('@')[1] + "/v2.0/.well-known/openid-configuration").Result.Content.ReadAsStringAsync().Result)).authorization_endpoint.ToString().Split('/')[3];                    
     
   IConfidentialClientApplication app = ConfidentialClientApplicationBuilder.Create(ClientId).WithClientSecret(clientSecret).WithTenantId(TenantId).Build();  
     
   var TokenResult = app.AcquireTokenForClient(new[] { scope }).ExecuteAsync().Result;                    
     
   System.Security.SecureString secureString = new System.Security.SecureString();                    
     
   foreach (char c in ("bearer " + TokenResult.AccessToken))                       
     
   secureString.AppendChar(c);                   
     
   String WSManURIConnectionString = "https://outlook.office365.com/powershell-liveid?DelegatedOrg=" + MailboxName.Split('@')[1] + "&BasicAuthToOAuthConversion=true";                   
     
   PSCredential credential = new PSCredential(MailboxName, secureString);                   
     
   WSManConnectionInfo connectionInfo = new WSManConnectionInfo(new Uri(WSManURIConnectionString), "http://schemas.microsoft.com/powershell/Microsoft.Exchange", credential);                   
     
   connectionInfo.AuthenticationMechanism = AuthenticationMechanism.Basic;                   
     
   connectionInfo.SkipCACheck = true;                   
     
   connectionInfo.SkipCNCheck = true;                   
     
    connectionInfo.MaximumConnectionRedirectionCount = 10;                   
     
   Runspace runspace = System.Management.Automation.Runspaces.RunspaceFactory.CreateRunspace(connectionInfo);                   
     
   if (runspace.RunspaceStateInfo.State == RunspaceState.Opened)                  
     
    {                       
     
   runspace.Close();                   
     
   }                   
     
   runspace.Open();                    
     
   // Make a Get-EXOMailbox requst using the Server Argument                   
     
   Command gmGetMailbox = new Command("Get-EXOMailbox");                   
     
   gmGetMailbox.Parameters.Add("ResultSize", "Unlimited");                   
     
   Pipeline plPileLine = runspace.CreatePipeline();                   
     
   plPileLine.Commands.Add(gmGetMailbox);                   
     
   Collection RsResultsresults = plPileLine.Invoke();                   
     
   plPileLine.Stop();                   
     
   plPileLine.Dispose();