Once you create an App ID, you must configure it for push notifications.
From the list of iOS App IDs, select the App ID to configure, then select
Settings.
Scroll down to the Push Notifications section and, under Development SSL
Certificate, select Create Certificate.
Here you can create both a Development SSL Certificate and a Production SSL
Certificate.
Follow the instructions for creating a Certificate Signing Request (CSR), select
Continue, then select Choose File to
locate the .certSigningRequest you created.
Click Generate.
Click Done once the certificate is ready, and download the
generated SSL certificate from the iOS App ID Settings screen.
Install the SSL in your Keychain.
In Keychain Access, under My Certificates, find the certificate you just
added, right-click on it, select Export Apple Development IOS Push
Services, and save it as a .p12 file.
Note: Do not enter an export password when prompted. You may, however, need to
enter your OSX password to allow Keychain Access to export the certificate
from your keychain.