Firebase push notification failed due to 401

Question

Used framework and librarys:

1. Backend --> spring boot
2. Frontend --> ionic angular
3. Push notification --> Firebase
4. Firebase library --> @awesome-cordova-plugins/[email protected], [email protected]

Error Faced:

1. Error showing in spring boot (firebase Admin) --> com.google.firebase.messaging.FirebaseMessagingException: Unexpected HTTP response with status: 401; body: null
2. Error showing from postman --> InvalidApnsCredential

Error Explaination: Near 30 push notification i was recieved properly, but few hours later the push notification is not working due to above 2 errors and also i was registered p8 file in firebase.

Working: For same project for android platform working fine but ios only facing above mentioned error