Я нашел ответ благодаря @ fredrik.
var client = new RestClient(url);
var request = new RestRequest(urlRequest, DataFormat.Json);
var response = client.Get(request);
Console.WriteLine(JsonSerializer.Deserialize<List<TestRestResponseTemplate>>(response.Content)[0].Entity.LegalName.Value);
TestRestResponseTemplate:
public class TestRestResponseTemplate
{
public Entity Entity { get; set; }
}
public class LegalName
{
[JsonPropertyName("@xml:lang")]
public string Language { get; set; }
[JsonPropertyName("$")]
public string Value { get; set; }
}
public class Entity
{
public LegalName LegalName { get; set; }
}