* 겪고 있는 문제 상황을 최대한 자세하게 작성해주세요.

* 문제 해결을 위해 어떤 시도를 해보았는지 구체적으로 함께 알려주세요.

강의나와있는 대로 따라 했는데 배너가 나오지 않습니다.

multidex 문제는 지난 질문들 참고하여 '[RN] :app:mergeExtDexDebug 에러 해결 방법 :: 香格里拉 (tistory.com)' 에서 해결하였습니다.

앱을 재실행해도 위젯 인스펙터에는 나외지만 배너는 보이지 않습니다.

app - build.gradle

plugins {
    id "com.android.application"
    id "kotlin-android"
    id "dev.flutter.flutter-gradle-plugin"
}


def localProperties = new Properties()
def localPropertiesFile = rootProject.file('local.properties')
if (localPropertiesFile.exists()) {
    localPropertiesFile.withReader('UTF-8') { reader ->
        localProperties.load(reader)
    }
}


def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
if (flutterVersionCode == null) {
    flutterVersionCode = '1'
}


def flutterVersionName = localProperties.getProperty('flutter.versionName')
if (flutterVersionName == null) {
    flutterVersionName = '1.0'
}



android {
    namespace "com.example.mymemo_admob"
    compileSdkVersion flutter.compileSdkVersion
    ndkVersion flutter.ndkVersion


    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }


    kotlinOptions {
        jvmTarget = '1.8'
    }


    sourceSets {
        main.java.srcDirs += 'src/main/kotlin'
    }


    defaultConfig {
        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
        applicationId "com.example.mymemo_admob"
        // You can update the following values to match your application needs.
        // For more information, see: https://docs.flutter.dev/deployment/android#reviewing-the-gradle-build-configuration.
        minSdkVersion 21
        targetSdkVersion flutter.targetSdkVersion
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
        multiDexEnabled true
    }


    buildTypes {
        release {
            // TODO: Add your own signing config for the release build.
            // Signing with the debug keys for now, so `flutter run --release` works.
            signingConfig signingConfigs.debug
        }
    }
    
}


flutter {
    source '../..'
}


dependencies {
    implementation 'androidx.multidex:multidex:2.0.1'
}

에러

Restarted application in 1,799ms.
D/DynamitePackage(10195): Instantiating com.google.android.gms.ads.ChimeraAdManagerCreatorImpl
I/Ads     (10195): Use RequestConfiguration.Builder().setTestDeviceIds(Arrays.asList("E6E74A089546AC2FB705B77F760E746D")) to get test ads on this device.
W/ConnectionStatusConfig(10195): Dynamic lookup for intent failed for action: com.google.android.gms.ads.service.START
E/JavaBinder(10195): !!! FAILED BINDER TRANSACTION !!!  (parcel size = 332)
W/GmsClient(10195): IGmsServiceBroker.getService failed
W/GmsClient(10195): android.os.DeadObjectException: Transaction failed on small parcel; remote process probably died, but this could also be caused by running out of binder buffe
W/GmsClient(10195): 	at android.os.BinderProxy.transactNative(Native Method)
W/GmsClient(10195): 	at android.os.BinderProxy.transact(BinderProxy.java:584)
W/GmsClient(10195): 	at m.app.s(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:177)
W/GmsClient(10195): 	at m.apm.a(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:14)
W/GmsClient(10195): 	at m.apo.c(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:7)
W/GmsClient(10195): 	at m.apf.d(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:7)
W/GmsClient(10195): 	at m.api.handleMessage(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:279)
W/GmsClient(10195): 	at android.os.Handler.dispatchMessage(Handler.java:106)
W/GmsClient(10195): 	at m.avi.a(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:1)
W/GmsClient(10195): 	at m.avi.dispatchMessage(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:1)
W/GmsClient(10195): 	at android.os.Looper.loopOnce(Looper.java:201)
W/GmsClient(10195): 	at android.os.Looper.loop(Looper.java:288)
W/GmsClient(10195): 	at android.os.HandlerThread.run(HandlerThread.java:67)
D/EGL_emulation(10195): app_time_stats: avg=19305.92ms min=472.90ms max=38138.94ms count=2
I/PlatformViewsController(10195): Hosting view in view hierarchy for platform view: 0
E/FrameEvents(10195): updateAcquireFence: Did not find frame.
W/Parcel  (10195): Expecting binder but got null!
E/FrameEvents(10195): updateAcquireFence: Did not find frame.
D/EGL_emulation(10195): app_time_stats: avg=43990.97ms min=43990.97ms max=43990.97ms count=1
I/Ads     (10195): Ad failed to load : 2
I/flutter (10195): banner error: LoadAdError(code: 2, domain: com.google.android.gms.ads, message: Network error., responseInfo: ResponseInfo(responseId: null, mediationAdapterClassName: , adapterResponses: [], loadedAdapterResponseInfo: null), responseExtras: {})
I/Ads     (10195): Ad failed to load : 2
I/flutter (10195): Ad with id `0` is not available for onAdFailedToLoad.
I/Ads     (10195): Use RequestConfiguration.Builder().setTestDeviceIds(Arrays.asList("E6E74A089546AC2FB705B77F760E746D")) to get test ads on this device.
I/le.mymemo_admob(10195): Background young concurrent copying GC freed 42121(3264KB) AllocSpace objects, 2(104KB) LOS objects, 38% free, 5080KB/8297KB, paused 1.841ms,333us total 119.116ms
W/ConnectionStatusConfig(10195): Dynamic lookup for intent failed for action: com.google.android.gms.ads.service.START
E/JavaBinder(10195): !!! FAILED BINDER TRANSACTION !!!  (parcel size = 332)
W/GmsClient(10195): IGmsServiceBroker.getService failed
W/GmsClient(10195): android.os.DeadObjectException: Transaction failed on small parcel; remote process probably died, but this could also be caused by running out of binder buffe
W/GmsClient(10195): 	at android.os.BinderProxy.transactNative(Native Method)
W/GmsClient(10195): 	at android.os.BinderProxy.transact(BinderProxy.java:584)
W/GmsClient(10195): 	at m.app.s(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:177)
W/GmsClient(10195): 	at m.apm.a(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:14)
W/GmsClient(10195): 	at m.apo.c(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:7)
W/GmsClient(10195): 	at m.apf.d(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:7)
W/GmsClient(10195): 	at m.api.handleMessage(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:279)
W/GmsClient(10195): 	at android.os.Handler.dispatchMessage(Handler.java:106)
W/GmsClient(10195): 	at m.avi.a(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:1)
W/GmsClient(10195): 	at m.avi.dispatchMessage(:com.google.android.gms.policy_ads_fdr_dynamite@233012805@233012802057.555274289.555274289:1)
W/GmsClient(10195): 	at android.os.Looper.loopOnce(Looper.java:201)
W/GmsClient(10195): 	at android.os.Looper.loop(Looper.java:288)
W/GmsClient(10195): 	at android.os.HandlerThread.run(HandlerThread.java:67)
I/Ads     (10195): Ad failed to load : 2
I/flutter (10195): Ad with id `0` is not available for onAdFailedToLoad.