Correct, no automatic backup. The backups have to be started manually, and can be encrypted or plain text or plain html.
I’m trying Ente without an Ente online account on Android so this is what I see.
You didn’t mention which phone type you have. If you have Android, you may want to consider Aegis. It has encrypted Android backup integration and can put encrypted files into a directory for your other off phone syncing.
You had another question about the usability of the Ente encrypted backups. I don’t think those can be used for anything other an Ente.