json and c#

I receive the following alert: Could not determine JSON object type for type System.Collections.Generic.Dictionary`2[System.String, System.String].
do you know why and how to fix it?


I expect to set the result:
{
  "action": "cancel",
  "registrants": [
    {
      "id": "1222",
      "email": "hello@gmail.com"
    }
  ]
}

            var model1 = new Dictionary<string, string>();
            model1.Add("id", "1222");
            model1.Add("email", "hello@gmail.com");

            dynamic test = new JObject();
            test.action = "Cancel";
            test.registrants = model1;

            Response.Write(test.ToString());