Example Singleton "MonoBehaviour"

MonoBehaviourSingletonExample.cs

using UnityEngine;

public class MonoBehaviourSingletonExample : MonoBehaviour
{
    public static MonoBehaviourSingletonExample Instance => _instance ?? Initialize();
    private static MonoBehaviourSingletonExample _instance;

    private static MonoBehaviourSingletonExample Initialize()
    {
        var instance = new GameObject();
        _instance = instance.AddComponent<MonoBehaviourSingletonExample>();
        DontDestroyOnLoad(_instance);
        return _instance;
    }
}