How to save exception in txt file?

class Program
   {
       static void Main(string[] args)
       {
           // SMTP server details
           int timeout = 1000; // Ping timeout in milliseconds

           try
           {
               var serverDetails = MailStatus.sqlUtility.GetSystemDetails();

               // Ping the SMTP server
               bool isServerUp =
                    PingServer(serverDetails.system_Address, timeout);

               // Save the result in SQL Server
               if (isServerUp)
               {
                   MailStatus.sqlUtility.SaveResultToDatabase
                       (serverDetails, isServerUp);
               }
           }
           catch (Exception ex)
           {
               //Console.WriteLine(ex.Message);
               LogExceptionToFile(ex);
           }

           Console.WriteLine("Ping completed.");
       }
       public static void LogExceptionToFile(Exception ex)
       {
           string logFilePath = "C:\\Projects\\\Logs\\SMTP\\SMTPlog.txt";

           //string logFilePath = "D:\\Projects\\Logs\\SMTP\\SMTPlog.txt";

           try
           {
               using (StreamWriter writer =
                      new StreamWriter(logFilePath, true))
               {
                   writer.WriteLine($"[{DateTime.Now}] Exception:
                                   {ex.GetType().FullName}");
                   writer.WriteLine($"Message: {ex.Message}");
                   writer.WriteLine($"Stack Trace: {ex.StackTrace}");
                   writer.WriteLine(new string('-', 40));
               }
           }
           catch (IOException)
           {
               // Handle any exceptions related to file access here
           }
       }