Rush • A new and improved way of building extensions

I am trying to compile my extension with Rush so that I can put ads in my app but the build failed.

I don't know where the problem is but I am going to post a picture.

The top arrow points to the line that I was instructed to add in this guide. How can I add admob extension to my app?
I do not know if the line is correct. For example, the star at the end of the line.
Furthermore, I don't know if the @UserPermissions line and the @UsesApplicationMetadata line are in the correct place.

Here's the text from this picture. (my .java file that was created when I ran
rush create <projectname>

package io.htwgadsext;

import com.google.appinventor.components.annotations.SimpleFunction;
import com.google.appinventor.components.runtime.AndroidNonvisibleComponent;
import com.google.appinventor.components.runtime.ComponentContainer;
import com.google.appinventor.components.runtime.errors.YailRuntimeError;
import com.google.appinventor.components.runtime.util.YailList;
import com.google.appinventor.components.annotations.androidmanifest.*;

public class Htwgadsext extends AndroidNonvisibleComponent {

public Htwgadsext(ComponentContainer container) {
super(container.$form());
}

@UsesPermissions(permissionNames = "")
@UsesApplicationMetadata(metaDataElements={@MetaDataElement(name="com.google.android.gms.ads.APPLICATION_ID", value="App-ID-Number")})

@SimpleFunction(description = "Returns the sum of the given list of integers.")
public int SumAll(YailList integers) {
int sum = 0;

for (final Object o : integers.toArray()) {
  try {
    sum += Integer.parseInt(o.toString());
  } catch (NumberFormatException e) {
    throw new YailRuntimeError(e.toString(), "NumberFormatException");
  }
}

return sum;

}

}

Here is the contents of the rush.yml file.

# For a detailed info on this file and supported fields, check out the below link:
# https://github.com/ShreyashSaitwal/rush-cli/wiki/Metadata-File

---
name: NameName
description: Extension component for PackageName. Created using Rush.

version:
  number: auto
  name: '1'

authors:
  - BlahBlah

build:
  release:
    # Optimizes the extension on every release build.
    optimize: true

  # If enabled, you will be able to use Java 8 language features in your extension.
  desugar:
    enable: false
    desugar_deps: false

assets:
  # Extension icon. This can be a URL or a local image in 'assets' folder.
  icon: icon.png
  # Extension assets.
  # other:
  #   - my_awesome_asset.anything

# Extension dependencies (JAR).
# deps:
#   - my_awesome_library.jar

Here is the xml file's contents.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="io.Package">
  <application>
    <!-- <activity android:name=".MainActivity">
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity> -->
  </application>
</manifest>

Thanks for any help!