After adding an MDM Server, you can test its outbound connectivity by clicking Enabling Push Notifications.while configuring the Apple Push Notifications service (APNs) or by clicking while configuring Firebase Cloud Messaging (FCM). If the configuration is valid, both these options will test the connection to the APNs and GCM servers from each of the MDM Servers. If the connectivity fails from one or more MDM Servers, the failed servers would be listed. You can perform these actions in the respective push notifications configuration sections of ZCC. For details, see
NOTE:If any ZCC operation involving an MDM Server fails, check the zcc.log, services-messages.log, and the loader-messages.log.