using System;

using System.Threading.Tasks;

using System.Text.Json;

public class Program

{

    public static async Task Main()

    {

        var test = "testASDDASda";

        var encoded = System.Web.HttpUtility.UrlEncode(test);

​

        Console.WriteLine(encoded);

        var decoded = System.Web.HttpUtility.UrlDecode(encoded);

        Console.WriteLine(decoded);

    }

}