LUKS is commonly used together with LVM. My laptap has a single NVME with almost no prospect of having additional disks installed, so in this use case LVM is nothing but unnecessary complexity. I know that in Linux, in principle, you can encrypt the root partition without using LVM at all. I have done it in other distros and I want to do it for my Debian 12 installation.
However, the Debian 12 installation UI does not seem to allow LUKS without LVM. AFAICT, in the guided partitioning, encryption entails LVM, and in manual partitioning, there is no way to specify that a partition is to be encrypted or specify a LUKS device (e.g. /dev/mapper/cryptroot) to be used as '/'.
Is it possible to have an encrypted root partition without LVM? If so, how can it be done?