Как исправить этот файл C#?

using UnityEngine;
using System.Collections;
using GoogleMobileAds.Api;

public class InterstitialAdScript : MonoBehaviour
{

    bool hasShownAdOneTime;

    void Start()
    {
        if (GameScript.isGameOver)
        {
            if (!hasShownAdOneTime)
            {
                hasShownAdOneTime = true;
                Invoke("showInterstitialAd", 60.0f);
            }
        }
    }
    
    public void showInterstitialAd()
    {
		 string adID = "ca-app-pub-";

      showInterstitialAd();

            //Stop Sound
            //

            Debug.Log("SHOW AD");
        }

    }
       
#if UNITY_ANDROID
        string adUnitId = adID;
    private static string adID;
    public object interstitialAd;
#elif UNITY_IOS
        string adUnitId = adID;
#else
        string adUnitId = adID;
#endif

   }

string adUnitId = adID;
private static string adID;
public object interstitialAd;