240
How the Signal Knockoff App TeleMessage Got Hacked in 20 Minutes
(www.wired.com)
This is a most excellent place for technology news and articles.
The only backup option I see for Signal is through Android, but it’s optional. There is no backup support for iOS or desktop.
https://support.signal.org/hc/en-us/articles/360007059752-Backup-and-Restore-Messages