Create Certificates

By Xcode

• Open Preferences -> Accounts
• Either select the right account or create new and login with the appropriate developer credentials
• On the right select the team with 'Agent' role. Click on View Details...
• In the Signing Identities section click create on iOS Development and iOS Distribution

By Certificate Signing Request

• Open Keychain Access, then navigate from the top menu to: Certificate Assistant -> Request a Certificate from Certificate Authority
• fill User Email Address with your apple developer account email
• Common Name is the name of the certificate and the private and public keys that will be generated for it. Fill with something meaningful.
• Select Saved to disk for Request is
• Go to Member center
• Go to 'Certificates, Identifiers & Profiles`
• Add a new certificate and choose either iOS App Development for development or App Store and Ad Hoc for distribution
• There will be instructions for creating Certificate Signing Request, on the next page. Click continue.
• Upload the CSR file and continue.
• There's no need to download it manually. Xcode has taken care of that.