Hello @timmy-zhou,   As PhilipDAth mentioned, this message regarding APNS certificate renewal can be safely disregarded if you no longer have need of this feature and no longer have any iOS or macOS devices enrolled in Systems Manager. However, if these devices are still enrolled and are required to be managed in Systems Manager, you will need to follow the steps in the documentation below to properly renew the APNS cert every 365 days: https://documentation.meraki.com/SM/Device_Enrollment/Apple_MDM_Push_Certificate#Renewing_an_Apple_MDM_Push_Certificate ... View more