https://support.signal.org/hc/en-us/articles/360007059752-Ba...
"Messages are only stored on your devices. Without an existing message history accessible to you account transfers are not supported."
So that means: no backup and restore. A backup means: I can still access my messages after my phone ends up at the bottom of a lake.
"Messages are only stored on your devices. Without an existing message history accessible to you account transfers are not supported."
So that means: no backup and restore. A backup means: I can still access my messages after my phone ends up at the bottom of a lake.