How can I migrate this to v12?
            var layer = new TiledWmsLayer();
            layer.ServerUris.Add(new Uri(Settings.CustomUri));
            layer.ActiveLayerNames.Add("osm");
            layer.SendingWebRequest += Backlayer_SendingWebRequest;
            if (!string.IsNullOrEmpty(Settings.MapKey) && !string.IsNullOrEmpty(Settings.GoogleClientId))
            {
                layer.ClientId = Settings.GoogleClientId;
                layer.PrivateKey = Settings.MapKey;
            }
        if (string.IsNullOrEmpty(Settings.WebProxy)) return new LayerOverlay(new BindingList<Layer> { layer });
        layer.WebProxy = CreateWebProxy() != null ? CreateWebProxy() : layer.WebProxy;
        layer.SendingWebRequest += LayerSendingWebRequest;
        return new LayerOverlay(new BindingList<Layer> { layer });