godot-ldtk-importer/addons/csharp_ldtk_importer/Models/LdtkLevel.cs

using System.Text.Json.Serialization;

namespace CSharpLdtkImporter.Models;

public class LdtkLevel
{
    [JsonPropertyName("identifier")]
    public string Identifier { get; set; }

    [JsonPropertyName("layerInstances")]
    public LdtkLayerInstance[] LayerInstances { get; set; }
}