I’m new to Android App Development, and I have read the documentation and watched a few videos about how to implement banner ads. However, I couldn’t get it figured out. I’m not too sure where I’m messing up on the AdMob implementation code. I can see the “Ads By Google” banner ad in my activity_main.xml, but I cannot see any ad previews when launching the app.

build.gardle.kts (in dependencies):

implementation(libs.play.services.ads)

MainActivity.kt (in onCreate):

MobileAds.initialize(this@MainActivity) {}
 adView = findViewById<View>(R.id.adView) as AdView
 val adRequest = AdRequest.Builder().build()
 adView.loadAd(adRequest)

AndroidManifest.xml:

<uses-permission android:name="android.permission.INTERNET"/>
 <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
 ...
 <meta-data
  android:name="com.google.android.gms.ads.APPLICATION_ID"
  android:value="(Insert App ID Here)"/>

activity_main.xml:

<com.google.android.gms.ads.AdView
  xmlns:ads="http://schemas.android.com/apk/res-auto"
  android:id="@+id/adView"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_centerHorizontal="true"
  android:layout_alignParentBottom="true"
  ads:adSize="BANNER"
  ads:adUnitId="(Insert Unit Id Here)"/>