Почему не показывает межстрвничную рекламу?

Question

[Chesterfield25]

У меня есть приложение и при его открытии должна показывается меж страничная реклама, но даже в тестовом режиме её не видно. Манифест настроен правильно и зависимости подключены.

import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.webkit.JavascriptInterface;
import android.webkit.WebResourceError;
import android.webkit.WebResourceRequest;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;

import com.google.android.gms.ads.AdError;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.FullScreenContentCallback;
import com.google.android.gms.ads.LoadAdError;
import com.google.android.gms.ads.MobileAds;
import com.google.android.gms.ads.initialization.InitializationStatus;
import com.google.android.gms.ads.initialization.OnInitializationCompleteListener;
import com.google.android.gms.ads.interstitial.InterstitialAd;
import com.google.android.gms.ads.interstitial.InterstitialAdLoadCallback;

public class MainActivity extends AppCompatActivity {

    WebView webView;
    private InterstitialAd mInterstitialAd;
    private int clickCount = 0;

    private static final String JS_INTERFACE_NAME = "AndroidInterface";

    @SuppressLint("WrongViewCast")
    @RequiresApi(api = Build.VERSION_CODES.O)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        webView = findViewById(R.id.webView);

        MobileAds.initialize(this, new OnInitializationCompleteListener() {
            @Override
            public void onInitializationComplete(InitializationStatus initializationStatus) {}
        });
        AdRequest adRequest = new AdRequest.Builder().build();

        InterstitialAd.load(this,"ca-app-pub-3940256099942544/1033173712", adRequest,
                new InterstitialAdLoadCallback() {
                    @Override
                    public void onAdLoaded(@NonNull InterstitialAd interstitialAd) {
                        // The mInterstitialAd reference will be null until
                        // an ad is loaded.
                        mInterstitialAd = interstitialAd;
                    }

                    @Override
                    public void onAdFailedToLoad(@NonNull LoadAdError loadAdError) {
                        // Handle the error
                        mInterstitialAd = null;
                    }
                });

        if (mInterstitialAd != null) {
            mInterstitialAd.show(MainActivity.this);
            mInterstitialAd.setFullScreenContentCallback(new FullScreenContentCallback(){
                @Override
                public void onAdClicked() {
                    // Called when a click is recorded for an ad.

                }

                @Override
                public void onAdDismissedFullScreenContent() {
                    // Called when ad is dismissed.
                    // Set the ad reference to null so you don't show the ad a second time.

                    mInterstitialAd = null;
                }

                @Override
                public void onAdFailedToShowFullScreenContent(AdError adError) {
                    // Called when ad fails to show.

                    mInterstitialAd = null;
                }

                @Override
                public void onAdImpression() {
                    // Called when an impression is recorded for an ad.

                }

                @Override
                public void onAdShowedFullScreenContent() {
                    // Called when ad is shown.

                }
            });
        }

        WebSettings webSettings = webView.getSettings();
        webView.getSettings().setJavaScriptEnabled(true);
        webView.clearCache(true);
        webView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
        webView.setDrawingCacheEnabled(true);

        webSettings.setAllowContentAccess(true);
        webSettings.setAllowFileAccess(true);

        webSettings.setDatabaseEnabled(true);
        webSettings.setDomStorageEnabled(true);

        webSettings.setLoadWithOverviewMode(true);

        final Activity activity = this;

        webView.setWebViewClient(new WebViewClient() {
            @SuppressWarnings("deprecation")
            @Override
            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
                Toast.makeText(activity, description, Toast.LENGTH_SHORT).show();
            }

            @TargetApi(android.os.Build.VERSION_CODES.M)
            @Override
            public void onReceivedError(WebView view, WebResourceRequest req, WebResourceError rerr) {
                // Redirect to deprecated method, so you can use it in all SDK versions
                onReceivedError(view, rerr.getErrorCode(), rerr.getDescription().toString(), req.getUrl().toString());
                webView.loadUrl("file:///android_asset/error.html");
            }
        });

        // Добавляем интерфейс для взаимодействия с JavaScript
        webView.addJavascriptInterface(new WebAppInterface(), JS_INTERFACE_NAME);

        webView.loadUrl("file:///android_asset/index.html");
    }

    // Класс для взаимодействия между WebView и JavaScripts
    public class WebAppInterface {
        @JavascriptInterface
        public void shareContent(String content) {
            // Выполните здесь свой код для обработки и передачи информации в социальные сети

            Intent intent = new Intent(
                    Intent.ACTION_SEND
            );
            intent.setType("text/plain");
            String Body = content;
            String Sub = "https://play.google.com/store/apps/details?id=com.buratinoapps.cryptocurrency.faucet.rotator";
            intent.putExtra(Intent.EXTRA_TEXT, Body);
            intent.putExtra(Intent.EXTRA_TEXT, Sub);
            startActivity(Intent.createChooser(intent, "Share using"));

            Toast.makeText(MainActivity.this, "Поделиться: " + content, Toast.LENGTH_SHORT).show();
        }

        public void showedAds() {

            if (mInterstitialAd != null) {
                mInterstitialAd.show(MainActivity.this);
                mInterstitialAd.setFullScreenContentCallback(new FullScreenContentCallback(){
                    @Override
                    public void onAdClicked() {
                        // Called when a click is recorded for an ad.

                    }

                    @Override
                    public void onAdDismissedFullScreenContent() {
                        // Called when ad is dismissed.
                        // Set the ad reference to null so you don't show the ad a second time.

                        mInterstitialAd = null;
                    }

                    @Override
                    public void onAdFailedToShowFullScreenContent(AdError adError) {
                        // Called when ad fails to show.

                        mInterstitialAd = null;
                    }

                    @Override
                    public void onAdImpression() {
                        // Called when an impression is recorded for an ad.

                    }

                    @Override
                    public void onAdShowedFullScreenContent() {
                        // Called when ad is shown.

                    }
                });
            }
        }
    }
}