Create btrfs witb Luks

I’m having problems with poweroff the system after a qube has more than 600Gb.
From what I read the best solution is to have the system in btrfs filesystem.

The problem is that if I folow these steps: Custom installation | Qubes OS I can format it only on ext4
What should I do to be able to have btrfs and luks?

No need to do this fully manually - the R4.0.4 installer can configure LUKS-encrypted btrfs:

  1. In the “INSTALLATION DESTINATION” screen, select “I will configure partitioning.” (If the destination disk isn’t empty already, you may also want to check “I would like to make additional space available.”)

  2. When the “MANUAL PARTITIONING” screen opens, switch the drop-down menu under “New mount points will use the following partitioning scheme:” from “LVM Thin Provisioning” to “Btrfs”, then press “Click here to create them automatically.”

Thank you @rustybird

Is it there a way to do this with custom installation to have aes256 and sha512 but btrfs?
Thanks