<com.app.ObservableWebView
    android:id="@+id/webview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    />

Create the InReadAdView dynamically:

private InReadAdView mAdView;    

protected void onCreate(Bundle savedInstanceState) {  
    super.onCreate(savedInstanceState);

    mAdView = new InReadAdView(getContext());
    mAdView.setPid(getPid());
    mAdView.setListener(new TeadsListener() {

        @Override
        public void onAdFailedToLoad(AdFailedReason adFailedReason) {
            // fallback logic
        }

        @Override
        public void onAdLoaded(float adRatio) {
            mWebviewHelperSynch.updateSlot(adRatio);
            mWebviewHelperSynch.displayAd();
        }

        @Override
        public void closeAd() {
            mWebviewHelperSynch.closeAd();
        }
    });
}

Implement SyncWebViewTeadsAdView.Listener to load the ad after the WebView is ready to receive one:

public class ArticleActivity extends AppCompatActivity implements SyncWebViewTeadsAdView.Listener {
    ...

    @Override
    public void onHelperReady(@NonNull ViewGroup adContainer) {
        //The helper is ready we can now load the ad
        if (mAdView != null) {
            mAdView.setAdContainerView(adContainer);
            mAdView.load(new AdSettings.Builder().pageUrl("https://example.com/article1").build());
        }
    }    
}

Create or update the WebViewClient that will listen for the WebView load

class CustomWebViewClient extends WebViewClient {

    private final SyncWebViewTeadsAdView mWebViewHelperSynch;

    private CustomWebViewClient(SyncWebViewTeadsAdView webviewHelperSynch) {
        mWebViewHelperSynch = webviewHelperSynch;
    }

    @Override
    public void onPageFinished(WebView view, String url) {
        mWebViewHelperSynch.injectJS();

        super.onPageFinished(view, url);
    }
}

Create the SyncWebViewTeadsAdView, the WebViewClient & enable JS in the WebView

mWebviewHelperSynch = new SyncWebViewTeadsAdView(mWebview, mAdView, this, "h2");

mWebview.getSettings().setJavaScriptEnabled(true);
mWebview.setWebViewClient(new CustomWebviewClient(mWebviewHelperSynch));

Load the data in the WebView

mWebview.loadUrl("https://example.com/article1");

Notify on configurationChange and destroy

@Override
public void onDestroy() {
    super.onDestroy();

    if (mAdView != null) {
        mAdView.clean();
    }
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    if (mWebviewHelperSynch != null) {
        mWebviewHelperSynch.onConfigurationChanged();
    }
}