I'm having trouble adding admob ads to the app

I want to add admob to my app, but when I add buildscript and allprojects to file project-level build.gradleI get a message all buildscript {} blocks must appear before any plugins {} blocks in the script

project-level build.gradle :

plugins {
id 'com.android.application' version '7.2.2' apply false
id 'com.android.library' version '7.2.2' apply false
}

task clean(type: Delete) {
delete rootProject.buildDir
}


buildscript {
repositories {
    google()
    mavenCentral()
}
}

allprojects {
repositories {
    google()
    mavenCentral()
}
}

build.gradle/app :

plugins {
id 'com.android.application'
}

android {
compileSdk 32

defaultConfig {
    applicationId "com.example.test"
    minSdk 28
    targetSdk 32
    versionCode 1
    versionName "1.0"

    testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
}

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

dependencies {

implementation 'com.google.android.gms:play-services-ads:21.2.0'
implementation 'androidx.appcompat:appcompat:1.5.0'
implementation 'com.google.android.material:material:1.6.1'
implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
testImplementation 'junit:junit:4.13.2'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'


}

Manifest :

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

<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.Test"
    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>