Getting an Apple® certificate for the Push Notification Bridge
For the Push Notification Bridge to connect to APNs, it must authenticate with a certificate. You can get a certificate from the Apple Developer Center.
Note:
These steps relate to the original APNs Provider API, where sandbox and production services each require a different certificate.
The Push Notification Bridge does not yet support the new APNs Provider API, which is based on HTTP/2 and requires only a single certificate for both sandbox and production roles.
For more information, see iOS Developer Library – App Distribution Guide.