This authorization file is a type of security key and is required to sign Apple certificates. You can use the same CSR file to create a push certificate and a distribution certificate for an app.

1. Open the application "keychain administration" from the Utilities folder on your Mac.
2. Select the following option from the top-tier drop-down menu "keychain administration" > "Certificate Assistant>> Request a Certificate from a Certification Authority ..."
3. Now enter the following information in the fields:
   • E-mail address of the user: your E-mail address
   • Common name: name of your publication
   • Please leave the field "E-Mail of the certification authority" free
   • Please choose the option "Save to disk" and continue
4. The file has now been generated and saved locally on your Mac. Now go back to the Apple Developer Portal and upload the CSR there.

The CSR file is required in the following steps:

1. Creating an iOS Distribution Certificate
2. Create / renew an Apple Push Certificate