Have you set up your /etc/crypttab to unlock your partitions after unlocking the root partition? I haven't had a setup where I needed to use multiple passphrases for unlocking so I'll leave that part for someone else (if it's even possible, you might have to use a custom encrypt hook?). But otherwise, see this for your keyfile partitions: https://wiki.archlinux.org/title/Dm-crypt/System_configuration#crypttab
Maybe also take a look at the LUKS on LVM section on the Arch wiki for potentially a little more guidance. Just ignore all the LVM instructions of course, they might as well be separate partitions
EDIT: I just noticed you're wanting to encrypt swap, which could be a headache depending on your needs (e.g. do you need hibernation?). See more here: https://wiki.archlinux.org/title/Dm-crypt/Swap_encryption
NOTE: I've provided links to the Arch wiki, but should be largely applicable to your set up