How to encrypt data in App.config

I would like to encrypt the keys (ApiKey and Secret) below in App.config:

<?xml version="1.0" encoding="utf-8" ?>
 <configuration>
  <startup> 
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
  </startup>
  <appSettings>
   <add key="ApiKey" value="sggrtdsfg"/>
   <add key="Secret" value="524524524"/>
  </appSettings>
</configuration>

I have already looked at several posts, some do by command line using "aspnet_regiis", but in my case it has to be via same code.

I created a console application, like this:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Configuration;

namespace CryptoTrader
{
    class Program
    {
      static void Main(string[] args)
      {
        CriptografarAppConfig();
      }

      static void CriptografarAppConfig()
      {
        Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
        ConfigurationSection section = config.AppSettings;

        if (!section.SectionInformation.IsProtected)
        {
           section.SectionInformation.ProtectSection("RSAProtectedConfigurationProvider");
           section.SectionInformation.ForceSave = true;
           config.Save();
        }
      }
    }
}

When the program runs, nothing happens simply! The App.config continues with the data without being encrypted, why does this occur?

Resolution: The code above works! The problem was that the App.config of the solution was not updated, but rather the CryptoTrader.exe.Config inside the CryptoTrader \ bin \ Debug folder and CryptoTrader \ bin \ Release

Source: link