Connect an app.config file on mac C#

using System;
using System.Configuration;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using OpenQA.Selenium;
using OpenQA.Selenium.Chrome;

namespace PrimoFramework
{
    [TestClass]
    public class UnitTest1
    {
        [TestMethod]
        public void TestMethod1()
        {

            Console.WriteLine(ConfigurationManager.AppSettings.Get("Browser"));
            Console.WriteLine(ConfigurationManager.AppSettings.Get("Username"));
            Console.WriteLine(ConfigurationManager.AppSettings.Get("Password"));

        
        }
    }
}

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
   <appSetting>

       <add key = "Browser" value="Chrome"/>
         <add key = "Username" value="nimanikravan@gmail.com"/>
          <add key = "Password" value="1995!Mille"/>

   </appSetting>
        
        
</configuration>

Quote:

This is my output:

Console.WriteLine(ConfigurationManager.AppSettings.Get("Browser"));
No return value.