Since missing certificates prevent electron auto updates from working, offer those users with a dialogue similar to that of "enable notifications" to join a room notifying them about updates instead:
Your platform doesn't support automatic updates for SchildiChat. Do you want to join a room notifying you about new releases?
No/Yes
Since missing certificates prevent electron auto updates from working, offer those users with a dialogue similar to that of "enable notifications" to join a room notifying them about updates instead: