Godot-Android-Admob-Plugin admon.gd to C#

Admob.cs

using Godot;

namespace AdmobLib
{
    public class Admob : Node
    {
        [Signal] public delegate void banner_loaded();
        [Signal] public delegate void banner_failed_to_load(int error_code);
        [Signal] public delegate void interstitial_failed_to_load(int error_code);
        [Signal] public delegate void interstitial_loaded();
        [Signal] public delegate void interstitial_closed();
        [Signal] public delegate void rewarded_video_loaded();
        [Signal] public delegate void rewarded_video_closed();
        [Signal] public delegate void rewarded(string currency, int ammount);
        [Signal] public delegate void rewarded_video_left_application();
        [Signal] public delegate void rewarded_video_failed_to_load(int error_code);
        [Signal] public delegate void rewarded_video_opened();
        [Signal] public delegate void rewarded_video_started();

        private bool _is_real;
        [Export]
        public bool is_real
        {
            get => _is_real;
            set
            {
                _is_real = value;
                init();
            }
        }
        [Export] public bool banner_on_top = true;
        [Export] public string banner_id;
        [Export] public string interstitial_id;
        [Export] public string rewarded_id;
        [Export] public bool child_directed = false;
        [Export] public bool is_personalized = true;
        [Export(PropertyHint.Enum, "G,PG,T,MA")] string max_ad_content_rate;

        // "private" properties
        // private Object _admob_singleton = null;
        private Object _admob_singleton = null;
        private bool _is_interstitial_loaded = false;
        private bool _is_rewarded_video_loaded = false;


        public override void _EnterTree()
        {
            GD.Print("Enter Tree");
            if (!init())
                GD.Print("AdMob Java Singleton not found");
        }

        // initialization
        private bool init()
        {
            if (Engine.HasSingleton("GodotAdMob"))
            {
                GD.Print("GetInstanceId() ", GetInstanceId());
                _admob_singleton = Engine.GetSingleton("GodotAdMob");
                _admob_singleton.Call(
                    "initWithContentRating",
                    is_real,
                    GetInstanceId(),
                    child_directed,
                    is_personalized,
                    max_ad_content_rate
                    );
                return true;
            }
            return false;
        }
        // load

        public void load_banner()
        {
            if (_admob_singleton != null)
                _admob_singleton.Call(
                    "loadBanner",
                    banner_id, banner_on_top);
        }
        public void load_interstitial()
        {
            if (_admob_singleton != null)
                _admob_singleton.Call(
                    "loadInterstitial",
                    interstitial_id);
        }

        public bool is_interstitial_loaded()
        {
            if (_admob_singleton != null)
                return _is_interstitial_loaded;
            return false;
        }

        public void load_rewarded_video()
        {
            if (_admob_singleton != null)
                _admob_singleton.Call(
                    "loadRewardedVideo",
                    rewarded_id);
        }

        public bool is_rewarded_video_loaded()
        {
            if (_admob_singleton != null)
                return _is_rewarded_video_loaded;
            return false;
        }

        // show / hide

        public void show_banner()
        {
            if (_admob_singleton != null)
                _admob_singleton.Call("showBanner");
        }
        public void hide_banner()
        {
            if (_admob_singleton != null)
                _admob_singleton.Call("hideBanner");
        }
        public void show_interstitial()
        {
            if (_admob_singleton != null)
            {
                _admob_singleton.Call("showInterstitial");
                _is_interstitial_loaded = false;
            }
        }

        public void show_rewarded_video()
        {
            if (_admob_singleton != null)
            {
                _admob_singleton.Call("showRewardedVideo");
                _is_rewarded_video_loaded = false;
            }
        }

        // resize

        public void banner_resize()
        {
            if (_admob_singleton != null)
            {
                _admob_singleton.Call("resize");
            }
        }

        // dimension

        public Vector2 get_banner_dimension()
        {
            if (_admob_singleton != null)
            {
                var width = (float)_admob_singleton.Call("getBannerWidth");
                var height = (float)_admob_singleton.Call("getBannerHeight");
                return new Vector2(width, height);
            }
            return new Vector2();
        }


        // callbacks

        public void _on_admob_ad_loaded()
        {
            GD.Print("banner_loaded");
            EmitSignal("banner_loaded");
        }

        public void _on_admob_banner_failed_to_load(int error_code)
        {
            GD.Print("banner_failed_to_load ", error_code);
            EmitSignal("banner_failed_to_load", error_code);
        }

        public void _on_interstitial_failed_to_load(int error_code)
        {
            _is_interstitial_loaded = false;
            GD.Print("interstitial_failed_to_load ", error_code);
            EmitSignal("interstitial_failed_to_load", error_code);
        }

        public void _on_interstitial_loaded()
        {
            _is_interstitial_loaded = true;
            GD.Print("interstitial_loaded");
            EmitSignal("interstitial_loaded");
        }

        public void _on_interstitial_close()
        {
            GD.Print("interstitial_closed");
            EmitSignal("interstitial_closed");
        }
        public void _on_rewarded_video_ad_loaded()
        {
            _is_rewarded_video_loaded = true;
            GD.Print("rewarded_video_loaded");
            EmitSignal("rewarded_video_loaded");
        }

        public void _on_rewarded_video_ad_closed()
        {
            GD.Print("rewarded_video_closed");
            EmitSignal("rewarded_video_closed");
        }
        public void _on_rewarded(string currency, int amount)
        {
            GD.Print("rewarded ", currency, " ", amount);
            EmitSignal("rewarded", currency, amount);

        }
        public void _on_rewarded_video_ad_left_application()
        {
            GD.Print("rewarded_video_left_application");
            EmitSignal("rewarded_video_left_application");
        }

        public void _on_rewarded_video_ad_failed_to_load(int error_code)
        {
            _is_rewarded_video_loaded = false;
            GD.Print("rewarded_video_failed_to_load ", error_code);
            EmitSignal("rewarded_video_failed_to_load", error_code);
        }

        public void _on_rewarded_video_ad_opened()
        {
            GD.Print("rewarded_video_opened");
            EmitSignal("rewarded_video_opened");
        }

        public void _on_rewarded_video_started()
        {
            GD.Print("rewarded_video_started");
            EmitSignal("rewarded_video_started");
        }

    }
}

I have a problem with this, the signals doesn't appear to be emitting so i added this function

public void connect_signals(){
    _admob_singleton.Connect("on_admob_ad_loaded", this, "_on_admob_ad_loaded");
    _admob_singleton.Connect("on_admob_banner_failed_to_load", this, "_on_admob_banner_failed_to_load");
    _admob_singleton.Connect("on_interstitial_failed_to_load", this, "_on_interstitial_failed_to_load");
    _admob_singleton.Connect("on_interstitial_loaded", this, "_on_interstitial_loaded");
    _admob_singleton.Connect("on_interstitial_close", this, "_on_interstitial_close");
    _admob_singleton.Connect("on_rewarded_video_ad_loaded", this, "_on_rewarded_video_ad_loaded");
    _admob_singleton.Connect("on_rewarded_video_ad_closed", this, "_on_rewarded_video_ad_closed");
    _admob_singleton.Connect("on_rewarded", this, "_on_rewarded");
    _admob_singleton.Connect("on_rewarded_video_ad_left_application", this, "_on_rewarded_video_ad_left_application");
    _admob_singleton.Connect("on_rewarded_video_ad_failed_to_load", this, "_on_rewarded_video_ad_failed_to_load");
    _admob_singleton.Connect("on_rewarded_video_ad_opened", this, "_on_rewarded_video_ad_opened");
    _admob_singleton.Connect("on_rewarded_video_started", this, "_on_rewarded_video_started");
}

and called it on init() just like in the gdscript version