Como Add Admob Android Studio com CardView e RecyclerView

Programação
#1

Olá, preciso colocar Admob no cardview INTERSTITIAL.

Como Add Admob Android Studio com CardView e RecyclerView

public class MainActivity extends AppCompatActivity {
private InterstitialAd mInterstitialAd;

List<Book> lstBook ;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

  //Admob 2020
    MobileAds.initialize(this, new OnInitializationCompleteListener() {
        @Override
        public void onInitializationComplete(InitializationStatus initializationStatus) {}
    });
    mInterstitialAd = new InterstitialAd(this);
    mInterstitialAd.setAdUnitId("ca-app-pub-3940256099942544/1033173712");
    mInterstitialAd.loadAd(new AdRequest.Builder().build());

    mInterstitialAd.setAdListener(new AdListener() {
        @Override
        public void onAdClosed() {
            // Load the next interstitial.
            mInterstitialAd.loadAd(new AdRequest.Builder().build());
            startActivity(new Intent(MainActivity.this,Book_Activity.class));
        }

    });

    //Admob 2020

    lstBook = new ArrayList<>();

CardView