This info is for app owners that have their own account or are planning to submit under their own dev accounts.
To enable push notifications in your app:
1. Go to Push Notifications screen.
2. Follow instructions to Create an APN Certificate and upload it.
3. If you have created already a .MOBILEPROVISION file, create a new one (only follow steps 9 .. 15 from http://support.brickandmobile.com/hc/en-us/articles/203656850-Distribution-Provisioning-Profile-MOBILEPROVISION-file-on-Apple)
4. If your application is already in AppStore, click Build Binaries and replace existing .MOBILEPROVISION with the new one. When binaries are ready, update them on itunesconnect.apple.com
5. When new binaries are approved, just go to Push Notifications screen, type your push message and hit Push button.