добавил кнопку

Assets/Resources/Data/RestartButton.asset

@@ -0,0 +1,16 @@
+%YAML 1.1
+%TAG !u! tag:unity3d.com,2011:
+--- !u!114 &11400000
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 0}
+  m_Enabled: 1
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+  m_Script: {fileID: 11500000, guid: 2842be317ca44ac1a2deed540475b267, type: 3}
+  m_Name: UnitSettings
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+  _speed: 9.8

Assets/RestartButton1.cs

@@ -0,0 +1,18 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class RestartButton1 : MonoBehaviour
+{
+    // Start is called before the first frame update
+    void Start()
+    {
+
+    }
+
+    // Update is called once per frame
+    void Update()
+    {
+
+    }
+}

Assets/Scripts/Controller/GameController.cs

@@ -26,6 +26,8 @@ private void LateUpdate()
             _controllers.LateExecute(deltaTime);
         }
 
+
+
         private void OnDestroy()
         {
             _controllers.Cleanup();

Assets/Scripts/Controller/NewBehaviourScript.cs

@@ -0,0 +1,18 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class NewBehaviourScript : MonoBehaviour
+{
+    // Start is called before the first frame update
+    void Start()
+    {
+
+    }
+
+    // Update is called once per frame
+    void Update()
+    {
+
+    }
+}

Assets/Scripts/Data/RestartButton.cs

@@ -0,0 +1,41 @@
+using UnityEngine;
+using UnityEngine.UI;
+using UnityEngine.SceneManagement;
+
+namespace MVCExample
+{
+    public sealed class Reference
+    {
+
+        private Canvas _canvas;
+        private Button _restartButton;
+
+        public Canvas Canvas
+        {
+            get
+            {
+                if (_canvas == null)
+                {
+                    _canvas = Object.FindObjectOfType<Canvas>();
+                }
+                return _canvas;
+            }
+        }
+
+        public Button RestartButton
+        {
+            get
+            {
+                if (_restartButton == null)
+                {
+                    var gameObject = Resources.Load<Button>("UI/RestartButton");
+                    _restartButton = Object.Instantiate(gameObject, Canvas.transform);
+                }
+
+                return _restartButton;
+            }
+        }
+
+    }
+
+}

Assets/Scripts/Interface/LevelRestart.cs

@@ -0,0 +1,18 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class LevelRestart : MonoBehaviour
+{
+    // Start is called before the first frame update
+    void Start()
+    {
+
+    }
+
+    // Update is called once per frame
+    void Update()
+    {
+
+    }
+}