If you are using a Branded App on Apple devices, you might receive the following message from Apple Developer Relations:
What to do?
Luckily, you don't need to do anything. This certificate is generated by the OfficeRnD engineering team and will be handled by our automation system.
As long as you granted us all the required permissions and accepted the latest Apple agreements, the certificate will be re-generated the next time we update your app to a newer version.
As it stands, push certificates are updated monthly. That is, if a certificate has one month remaining, it will be re-generated automatically.
Moreover, even if the certificate expires, the app will remain in the App Store and you will always be able to use it. However, push notifications won't be sent until the certificate has been regenerated.