1. Open App IDs in Apple developer portal:
2. Choose the app Id you want to update its certificate and click on Edit
3. Scroll down to Push notifications and click on create certificate:
You’ll have to choose if you’re using production or development certificate for your app.
Follow apple instructions to create it, then click on Download:
4. Open the downloaded file, it’ll open Keychain, Add to login if asked to.
5. Search in keychain for your application Identifer:
6. Right click on it and click Export …:
Don’t enter a password for it then click ok:
7. click on settings below the app:
Open Push tab and click on Upload push Certificate:
Choose the p12 file you’ve just exported from keychain and you’re done :D