How to read mails from exchange server by using Pop3 protocol in VS2022

Question

I was using below c# code in Visual studio 2022 to read mails from exchange server folder testmail and getting error as ERR Logon failure: unknown user name or bad password at line below. telnet is working and even same account i added in microsoft outlook 365,so password also correct.Do i need to replace basic authentication with Oauth? if so how i can change below code since i already have tenant key ,app key and clientSecret

  string statCommand = $"STAT\r\n";
  SendCommand(sslStream, statCommand);

Full Code is as below

   string pop3Server = "pop3.test.corp.ae"; // Replace with your POP3 server
   int pop3Port = 995; // SSL port
   string username = "testmail@test.com";
   string password = "1234ere";

   // Path to the client certificate
   string certificatePath = @"D:\test\test.crt";
   string certificatePassword = "";

//    System.Net.ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Tls12;
//    Pop3Client pop3Client = new Pop3Client();
    //pop3Client.Connect(pop3Server, pop3Port, true);
    //pop3Client.Authenticate(username, password);
    // Load the client certificate
    X509Certificate2 clientCertificate = new X509Certificate2(certificatePath);//certificatePassword);

    // Connect to the POP3 server
    using (TcpClient client = new TcpClient(pop3Server, pop3Port))
    using (SslStream sslStream = new SslStream(
        client.GetStream(),
        false,
        new RemoteCertificateValidationCallback(ValidateServerCertificate),
        null))
    {
        // Authenticate using SSL with the client certificate
        sslStream.AuthenticateAsClient(pop3Server, new X509CertificateCollection { clientCertificate }, System.Security.Authentication.SslProtocols.Tls12, false);

        // Send POP3 commands to authenticate and retrieve emails
        string loginCommand = $"USER {username}\r\n";
        SendCommand(sslStream, loginCommand);

        string passCommand = $"PASS {password}\r\n";
        SendCommand(sslStream, passCommand);
}
 static void SendCommand(SslStream sslStream, string command)
 {
     byte[] buffer = Encoding.ASCII.GetBytes(command);
     sslStream.Write(buffer, 0, buffer.Length);
     sslStream.Flush();

     // Read server response (if needed)
     byte[] responseBuffer = new byte[2048];
     int bytesRead = sslStream.Read(responseBuffer, 0, responseBuffer.Length);
     string response = Encoding.ASCII.GetString(responseBuffer, 0, bytesRead);

     Console.WriteLine(response);
 }

EDIT There was String Interpolation issue i have to replace @ with $... So now for

string loginCommand = $"USER {username}\r\n";

i am getting response as +OK The Microsoft Exchange POP3 service is ready and for string passCommand = $"PASS {password}\r\n"; i am getting response as +OK but for string statCommand = $"STAT\r\n";

I am getting response as -ERR Logon failure: unknown user name or bad password