[Unity]Oculusのハンドトラッキングでボタンを押したい。

using System;
using UnityEngine;
using OculusSampleFramework;

public class StartButton : MonoBehaviour
{
    
    [SerializeField] private StartButton _buttonController;

    public void ActionButton()
    {

        // ButtonのActionZoneに触れている時
        _buttonController.ActionZoneEvent += args =>
        {
            if (args.InteractionT == InteractionType.Enter)
            {
                Debug.Log("Push");//ボタンをクリックした時の処理
            }
        };
    }

}

'StartButton' does not contain a definition for 'ActionZoneEvent' and no accessible extension method 'ActionZoneEvent' accepting a first argument of type 'StartButton' could be found (are you missing a using directive or an assembly reference?)