ModelProject/Assets/Scripts/Singleton.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public abstract class Singleton<T> where T:class, new()
{
    protected static T _instance = null;
    public static T Instance
    {
        get
        {
            if(_instance == null)
            {
                _instance = new T();
            }
            return _instance;
        }
    }

    protected Singleton()
    {
        if(_instance != null)
        {
            Debug.LogError("This" + (typeof(T)).ToString() + "Singleton Instance is not null");
        }
        Init();
    }
    public virtual void Init()
    {

    }
}