I'm actually just looking into LUKS on Hetzner.

I've found this - how to do it without ever entrusting any encryption key to Hetzner

https://www.tqdev.com/2023-luks-encrypted-debian-12-server-h...

But it seems like way too much work

There is this easy tutorial (that for some reason disappeared)

https://web.archive.org/web/20260128114859/https://community...

and this on how to get an email when you need to unlock it via SSH

https://dominik.wombacher.cc/posts/email_notification_to_unl...