Ope Existing Firefox browser in Selenium

UnitTest1.cs

using Microsoft.VisualStudio.TestTools.UnitTesting;
using OpenQA.Selenium;
using OpenQA.Selenium.Firefox;
using System;

namespace SeleniumTest
{
    [TestClass]
    public class UnitTest1
    {
        IWebDriver driver;
        [TestMethod]
        public void TestMethod1()
        {
            string gec_path = @"C:\Users\rathr1\Downloads\geckodriver-v0.28.0-win64";
            string firefox = @"C:\Data\testfirefox\firefox.exe";
            string profile_dir = @"C:\Data\testfirefox\prof\";
            

            FirefoxOptions options = new FirefoxOptions();
            options.AddArguments("--disable-extensions");
            options.AddArgument("--ignore-certificate-errors");
            options.Profile = new FirefoxProfile(profile_dir); // This should be the non-empty firefox profile directory.

            FirefoxDriverService service = FirefoxDriverService.CreateDefaultService(gec_path, "geckodriver.exe");
            service.FirefoxBinaryPath = firefox;

            service.SuppressInitialDiagnosticInformation = true;
            service.HideCommandPromptWindow = true;  
                
            driver = new FirefoxDriver(service, options, TimeSpan.FromMinutes(1));
            driver.Manage().Window.Maximize();
            driver.Navigate().Refresh();
        }

        [TestCleanup]
        public void ShutDown()
        {
                driver?.Quit();
        }
    }
}