Renew a push notification certificate in macOS Server
You must periodically renew certificates used to provide encrypted notification. Renewing a certificate creates a new certificate with a new expiration date.
- In the sidebar of the Server app  , select the server, select Profile Manager, then click Configure under Device communication push notification certificate. , select the server, select Profile Manager, then click Configure under Device communication push notification certificate.
- Next to the expiration date, click Renew. 
- Enter the Apple ID and password. 
- Click Renew Certificate.