push notifications issue

A push could not be sending for various reasons:

• Navigate to the User Profiles and make sure that the users are subscribed (or opted in) to Push.
• Ensure that users are Push Registered for the app with a valid push token.
• Check the push changelog as it is possible that the token might have been removed or changed.
• Verify the correct type of push notification is being sent out.
• Confirm that the user is part of the segment – You can use the "user lookup" functionality to do this.
• Ensure you are not targeting a FireTV with an Android push campaign when you should be using a Kindle push.
• Check if your developers need to update the push certificate or GCM Project ID. This is something that needs to be done in the dashboard.
• Confirm whether notifications are being received when being sent by Firebase or APNS directly. If not, it's likely a Braze integration issue.
• Make sure the correct API key is inputted into the app code.
  iOS Push Troubleshooting Guide 
  Android Push Troubleshooting Guide