Full screen mode game view in editor

I am trying to make my game view full screen and I have found few scripts online in order to achieve this. Unfortunately I am not able to execute them in 2020 version (or 2018+). Is there a method to enable full screen game window during editor mode? From the below script, I get exception error at System.Object Res = GetMainGameView.Invoke (null, null); Is the current Unity version not accessible for the GetMainGameView?

using UnityEditor;
using UnityEngine;

namespace FullScreenPlayModes {
    [InitializeOnLoad]
    public class FullScreenPlayMode : Editor {
        //The size of the toolbar above the game view, excluding the OS border.
        private static int toolbarHeight = 22;

        static FullScreenPlayMode () {
            EditorApplication.playModeStateChanged -= PlayModeStateChanged;
            EditorApplication.playModeStateChanged += PlayModeStateChanged;
        }

        static void PlayModeStateChanged (PlayModeStateChange _playModeStateChange) {
            if (PlayerPrefs.GetInt ("PlayMode_FullScreen", 0) == 1) {
                // Get game editor window
                EditorApplication.ExecuteMenuItem ("Window/General/Game");
                System.Type T = System.Type.GetType ("UnityEditor.GameView,UnityEditor");
                System.Reflection.MethodInfo GetMainGameView = T.GetMethod ("GetMainGameView", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static);
                System.Object Res = GetMainGameView.Invoke (null, null);
                EditorWindow gameView = (EditorWindow) Res;

                switch (_playModeStateChange) {
                    case PlayModeStateChange.EnteredPlayMode:

                        Rect newPos = new Rect (0, 0 - toolbarHeight, Screen.currentResolution.width, Screen.currentResolution.height + toolbarHeight);

                        gameView.position = newPos;
                        gameView.minSize = new Vector2 (Screen.currentResolution.width, Screen.currentResolution.height + toolbarHeight);
                        gameView.maxSize = gameView.minSize;
                        gameView.position = newPos;

                        break;

                    case PlayModeStateChange.EnteredEditMode:

                        gameView.Close ();

                        break;
                }
            }
        }

        [MenuItem ("Tools/Editor/Play Mode/Full Screen", false, 0)]
        public static void PlayModeFullScreen () {
            PlayerPrefs.SetInt ("PlayMode_FullScreen", 1);
        }

        [MenuItem ("Tools/Editor/Play Mode/Full Screen", true, 0)]
        public static bool PlayModeFullScreenValidate () {
            return PlayerPrefs.GetInt ("PlayMode_FullScreen", 0) == 0;
        }

        [MenuItem ("Tools/Editor/Play Mode/Window", false, 0)]
        public static void PlayModeWindow () {
            PlayerPrefs.SetInt ("PlayMode_FullScreen", 0);
        }

        [MenuItem ("Tools/Editor/Play Mode/Window", true, 0)]
        public static bool PlayModeWindowValidate () {
            return PlayerPrefs.GetInt ("PlayMode_FullScreen", 0) == 1;
        }
    }
}