AppCenter Push notification implementation

Hi guys,
I'm trying to work out how to implement push notification with AppCenter. I followed the instructions for each platform (iOS, Android and UWP) but there are some issues.

• Android: I added Microsoft.AppCenter.Push, in the AndroidManifest what I found in the AppCenter instruction and add google-services.json. After that I'm receiving the following error.

Java.Lang.RuntimeException: String resource ID #0x7f09001a

<application android:label="MyApp.Android">
    <receiver android:name="com.google.firebase.iid.FirebaseInstanceIdInternalReceiver" android:exported="false" />
    <receiver android:name="com.google.firebase.iid.FirebaseInstanceIdReceiver" android:exported="true" android:permission="com.google.android.c2dm.permission.SEND">
        <intent-filter>
            <action android:name="com.google.android.c2dm.intent.RECEIVE" />
            <action android:name="com.google.android.c2dm.intent.REGISTRATION" />
            <category android:name="${applicationId}" />
        </intent-filter>
    </receiver>
</application>

What is the correct implementation? How can I display then a Toast?

• UWP: I received the message from AppCenter but how I can display a message? What is the implementation if the app is closed?
• iOS: is there an implementation that I can follow?

Thank you guys in advance!