using System;

using System.Text.Unicode;

using System.Text.Encodings.Web;

using System.Text.Json;

using System.Text.Json.Nodes;

public class Program

{

    public static void Main()

    {

        JsonObject obj = new JsonObject()

        {

            ["Test"] = "It's a test"

        };

        var encoderSettings = new TextEncoderSettings();

        encoderSettings.AllowCharacters('\u0027');

        encoderSettings.AllowRange(UnicodeRanges.All);

        JsonSerializerOptions serializerSettings = new JsonSerializerOptions

        {

            Encoder = JavaScriptEncoder.Create(encoderSettings)

        };

        string serialized = JsonSerializer.Serialize(obj, serializerSettings);

        Console.WriteLine(serialized);

    }

}