Playing with qubes part 2

How is it possible to configure crypttab and dracut to find the detached LUKS header (which would normally be at /dev/sda3) by using UUID instead of by drive location, as instructed in the guide:

echo -e “luks-$uuidR /dev/nvme0n1 /etc/keys/root.key luks,discard,key-slot=1,header=/dev/sda3\nluks-$uuidB UUID=$uuidB /etc/keys/boot.key luks,key-slot=1” > /etc/crypttab

This snippet here: header=/dev/sda3\nluks-$uuidB means what exactly? My understanding is that the header at /dev/sda3 will be used to decrypt the drive, but if the USB happens to be moved and it can’t be found at /dev/sda3, does this mean that it will instead search for luks-$uuidB? Please clarify. Thank you.

Any idea how this is possible @51lieal