Create a key with APNs enabled
Click + under Keys, name the key, tick Apple Push Notification service and click Configure. Choose the environment (Sandbox or Production) and key type: team-scoped (any topic in the team, max two per environment) or topic-specific (chosen topics, max 200 per environment). Review and confirm.
If something goes wrong (1)
- You cannot create another team-scoped key.: Each environment allows at most two team-scoped keys. Revoke an unused one (check nothing depends on it first) or use a topic-specific key. [1]
Where: https://developer.apple.com/account/resources