I can't add admob banner and Interstitial ad to my webview(Html css Javascrit) android test project

Ads not loading when app is opened. I did not add anything to the HTML or Javascript files, other than the code block I wrote myself, this is what I could do by searching on the internet. English spelling may be wrong, I write with Google Translate

build.grade.kts:

plugins {
    id("com.android.application")
}

android {
    namespace = "com.example.myapp"
    compileSdk = 34

    defaultConfig {
        applicationId = "com.example.myapp"
        minSdk = 22
        targetSdk = 34
        versionCode = 1
        versionName = "1.0"

        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            isMinifyEnabled = false
            proguardFiles(
                getDefaultProguardFile("proguard-android-optimize.txt"),
                "proguard-rules.pro"
            )
        }
    }
    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_1_8
        targetCompatibility = JavaVersion.VERSION_1_8
    }
}

dependencies {

    implementation("androidx.appcompat:appcompat:1.6.1")
    implementation("com.google.android.material:material:1.11.0")
    implementation("com.google.android.gms:play-services-ads:22.6.0") // Buraya eklendi
    testImplementation("junit:junit:4.13.2")
    androidTestImplementation("androidx.test.ext:junit:1.1.5")
    androidTestImplementation("androidx.test.espresso:espresso-core:3.5.1")
}

AndroidManifest.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <!-- AdMob izinleri ekle -->
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.Myapp"
        tools:targetApi="31">

        <activity android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <meta-data
            android:name="com.google.android.gms.ads.APPLICATION_ID"
            android:value="ca-app-pub-3940256099942544~3347511713" />

    </application>

</manifest>

MainActivity.java

package com.example.myapp;

import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import androidx.appcompat.app.AppCompatActivity;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;
import com.google.android.gms.ads.MobileAds;
import com.google.android.gms.ads.initialization.InitializationStatus;
import com.google.android.gms.ads.initialization.OnInitializationCompleteListener;

public class MainActivity extends AppCompatActivity {

    private WebView webView;
    private AdView mAdView;

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

        webView = findViewById(R.id.webView);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.setWebViewClient(new WebViewClient());

        // Kullanılacak olan HTML dosyasının adını değiştirin
        webView.loadUrl("file:///android_asset/index.html");

        // AdMob reklam bannerını yükle
        MobileAds.initialize(this, new OnInitializationCompleteListener() {
            @Override
            public void onInitializationComplete(InitializationStatus initializationStatus) {
                mAdView = findViewById(R.id.adView);
                AdRequest adRequest = new AdRequest.Builder().build();
                mAdView.loadAd(adRequest);
            }
        });
    }

    // Android cihazın geri tuşuna basıldığında WebView'i kontrol eder
    @Override
    public void onBackPressed() {
        if (webView.canGoBack()) {
            webView.goBack();
        } else {
            super.onBackPressed();
        }
    }
}

acivity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <WebView
        android:id="@+id/webView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <com.google.android.gms.ads.AdView
        android:id="@+id/adView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        app:adSize="BANNER"
        app:adUnitId="ca-app-pub-3940256099942544/6300978111" />

</RelativeLayout>

It looks like you forget to initialize ad sdk. Check these steps:

1. Make sure you added ad app id in your manifest.xml

<manifest>
<application>
  <!-- Sample AdMob app ID: ca-app-pub-3940256099942544~3347511713 -->
  <meta-data
      android:name="com.google.android.gms.ads.APPLICATION_ID"
      android:value="ca-app-pub-xxxxxxxxxxxxxxxx~yyyyyyyyyy"/>

           ...

  </application>
</manifest>

2. Initialize mobile sdk in your MainActivity's onCreate adn load ad after MobileAds initialization.

MobileAds.initialize(this, new OnInitializationCompleteListener() {
   @Override
   public void onInitializationComplete(InitializationStatus initializationStatus) {
    //Now you can load ad
    AdRequest adRequest = new AdRequest.Builder().build();
    adView.loadAd(adRequest);
        }
});

For more details look at Android docs.