Problem with System.PlatformNotSupportedException

[DeafMan1983]

Hello @HurricanKai , junger Deutscher 👍 Ich weiß schon dass du jüngster Programmierer. Ich bin auch Deutscher :D

Sorry I contact with @HurricanKai on German Language.
I would like to show about GtkSharp 3 with GLFW3 via glfwGetX11Window()

I made code below:

using System;
using System.Runtime.InteropServices;
using Silk.NET.Maths;
using Silk.NET.OpenGL;
using Silk.NET.Windowing;

namespace GLFWOnGtk3
{
    unsafe class Program
    {
        private const string libgdk = "gdk-3";
        private const string libglfw = "glfw.so.3";
        
        [DllImport(libgdk)]
        private static extern IntPtr gdk_x11_display_get_xdisplay(IntPtr gdk_display);

        [DllImport(libgdk)]
        private static extern IntPtr gdk_x11_window_foreign_new_for_display(IntPtr gdk_display, IntPtr x_window);

        [DllImport((libglfw))]
        private static extern IntPtr glfwGetX11Window(nint glfw_window);

        private static IWindow glfw_win;
        private static GL gl;
        
        static void Main(string[] args)
        {
            Gtk.Application.Init();

            Gdk.Display gd = Gdk.Display.Default;
            
            var opts = WindowOptions.Default;
            opts.Size = new Vector2D<int>(200, 200);
            Window.PrioritizeGlfw();
            glfw_win = Window.Create(opts);
            glfw_win.Initialize();
            glfw_win.Render += OnRender;
            glfw_win.Closing += OnClose;
            glfw_win.Run();

            IntPtr x_window = glfwGetX11Window(glfw_win.Handle);
            Gdk.Window gw = new Gdk.Window(gdk_x11_window_foreign_new_for_display(gd.Handle, x_window));
            
            Gtk.Window gtk_window = new Gtk.Window(Gtk.WindowType.Toplevel);
            gtk_window.Realized += delegate {
                gtk_window.Window = gw;
            };

            gtk_window.HasWindow = true;
            gtk_window.Realize();

            bool running = true;
            while (running)
            {
                if (Gdk.Events.Pending())
                {
                    Gtk.Application.RunIteration();
                }
            }
        }

        private static void OnRender(double obj)
        {
            gl = GL.GetApi(glfw_win);
            
            gl.Clear(ClearBufferMask.ColorBufferBit);
            gl.ClearColor(1.0f, 1.0f /3, 0f, 1.0f);
        }
        
        private static void OnClose()
        {
            Gtk.Application.Quit();
        }
    }
}

After compilation was successfully.
I try to open with dotnet run
It throws exception:

Unhandled exception. System.PlatformNotSupportedException: Couldn't find a suitable window platform. https://docs.ultz.co.uk/silk.net/windowing/troubleshooting.html
   at Silk.NET.Windowing.Window.Create(WindowOptions options)
   at GLFWOnGtk3.Program.Main(String[] args) in /home/jens/RiderProjects/TestForGLFW/GLFWOnGtk3/Program.cs:line 35

Is it better then System.Runtime... DLLImport - I need use NativeApi, correctly?

Thanks!