jsTree - parsing li_attr from JSON

[pskalnik]

Hi,
in ASP.NET MVC I have model defined like

namespace ASPCoreJSON.Models { public class AlbumData { public int userId { get; set; } public int id { get; set; } public string title { get; set; } public string? icon { get; set; } public string? li_attr { get; set; } = string.Empty; } }
When parsing JSON
{
"userId": 2,
"id": 11,
"title": "quam nostrum impedit mollitia quod et dolor",
"li_attr": {"class": "red"}
}

like:
var json = webClient.DownloadString(@"Albums.json"); var albums = JsonConvert.DeserializeObject<List<AlbumData>>(json);

Error:
Newtonsoft.Json.JsonReaderException: Unexpected character encountered while parsing value: {. Path '[10].li_attr', line 57, position 16.

The wrong character is "{" in li_attr JSON. How I need to declare it in JSON to be able to Deserialize it correctly with Newtonsoft.Json???

Thank you!