Encrypting RAID1

I’m setting up a nextcloud server with two HDDs for storage. I want to have redundancy in case a drive fails (hence RAID1) and I don’t want to worry about where I might forget the drives one day (hence the encryption). I’m going to be storing data for other people as well, so I think that alone requires encryption.

I’ve been doing some reading and found this:
It seems to suggest encrypting the drives first and then combining them to a logical volume to be mounted somewhere.
The advice in ancient (2007), so is there a better way of doing this?
I’m not sure I want to use zfs because I’m not sure if it can be encrypted and I’d like to be able to add a third HDD in the future for a RAID5 array. That said, I’m open for suggestions.

I am using Ubuntu server 20.04 btrfs inside a luks encrypted raid1 on two disks and this works fine for me. The cool thing is that you can create raid1 after you have actually set up your system. I will have a guide in this shortly on my homepage (Installation guides | Willi Mutschler) I already have one for Pop!_OS so you can already have a look as the procedures is almost the same…

Note, though, that RAID5 is Not supported or very problematic with btrfs. Also in case one of your disks breaks in a raid1 with two disks (you can actually do more disks in Raid1), There are some hiccups as by default you can only reboot once in read write degraded mode to either replace the drive or make the working drive single again. After that degraded mode reboots will make your drive read only unless you path a kernel module. When my drive broke a couple of months ago, I simply rebooted in a live system and repaired everything there.