Let’s look at the extra configurations that can be done on your air-gapped workspace.
Push Notification Configuration
In an air-gapped workspace, sending push notifications through FCM/APNS isn't possible as they rely on internet connectivity. However, if the air-gapped server is considered a regular server with a strong firewall, outbound traffic can be configured to allow push notifications by opening specific ports as per FCM and APNS guidelines. Nevertheless, this approach may compromise the air-gapped environment's security and should be carefully considered.
For fully air-gapped workspaces, you have to build a Rocket.Chat app for your desired mechanism. To learn more, visit Rocket.Chat Apps-Engine.