Interstitial show back

Only when starting the game is calling interstitial.
How do I get the Interstitial show in all three games? what should I do?

periodically I want to call but could not find. my basic code is below

Code (CSharp):

1.  
2.   using System.Collections;
3.   using System.Collections.Generic;
4.   using UnityEngine;
5.   using GoogleMobileAds.Api;
6.  
7.   public class Interstitial : MonoBehaviour
8.  
9.   {
10.       InterstitialAd interstitial;
11.  
12.       // Use this for initialization
13.  
14.       void Start()
15.       {
16.   #if UNITY_ANDROID
17.           string appId = "Admob ID";
18.   #elif UNITY_IPHONE
19.               string appId = "ca-app-pub-3940256099942544~1458002511";
20.   #else
21.           string appId = "unexpected_platform";
22.   #endif
23.  
24.           // Initialize the Google Mobile Ads SDK.
25.           MobileAds.Initialize(appId);
26.  
27.  
28.      
29.      
30.          
31.      
32.   #if UNITY_ANDROID
33.       string adUnitId = "ca-app-pub-3940256099942544/1033173712";
34.   #elif UNITY_IPHONE
35.           string adUnitId = "ca-app-pub-3940256099942544/4411468910";
36.   #else
37.           string adUnitId = "unexpected_platform";
38.   #endif
39.  
40.           // Initialize an InterstitialAd.
41.           this.interstitial = new InterstitialAd(adUnitId);
42.  
43.  
44.  
45.           // Create an empty ad request.
46.           AdRequest request = new AdRequest.Builder()
47.               .AddTestDevice("2077ef9a63d2b398840261c8221a0c9b")
48.               .Build();
49.           // Load the interstitial with the request.
50.           this.interstitial.LoadAd(request);
51.  
52.  
53.  
54.       }
55.  
56.       void Update()
57.  
58.       {
59.  
60.           if (this.interstitial.IsLoaded())
61.  
62.           {
63.               this.interstitial.Show();
64.  
65.  
66.           }
67.  
68.                  
69.  
70.  
71.       }
72.  
73.       void OnDestroy()
74.       {
75.  
76.           interstitial.Destroy(); //Destroy
77.  
78.          
79.       }

 

With this code, you are trying to show an ad about 60 times a second in your Update method. Only call Show when you need it!

 

So what to do.

 

Sorry, I don't follow. You have Show working, only call it when you need to! Where in your game do you want ads to show? That is where you place your Show method. You mention "all three games", did you mean scenes? For starters as you are learning the platform, I might suggest putting a test button on your scene, and showing an ad in the click event for the button, and go from there.