To resolve, you’ll need to create an Identifier on developer.apple.com called: [yourbundleID].ImageNotification. Here's a link to the instructions on how to do this.
Adding the Identifier
You must add an Identifier to be able to send the push notifications to the iOS devices after you deploy your app to the app store.
To add an Identifier:
From your Apple developer account open the Identifiers section.
Click on the (+) button on the right side of the Identifiers label.
Select the App IDs and click Continue.
Select the Type App and click Continue.
Enter the Description as ImageNotification.
Enter the Bundle ID as your package name and add .ImageNotification in the end.
Click Continue and then click Register.