How to open an USB's encrypted /boot automatically

My situation is a bit unique: The scenario ~ I have successfully encrypted my root partition and boot partitions. My boot partition lies on my usb along with the /boot/efi on a separate unencrypted partition on the usb. I use grub and my system works fine as is. But, I would love to skip the boot password (since i will keep my usb secure) and really just encrypted the /boot partition as a just in case measure. So, I have a keyfile already linked to the /boot partition and its well hidden and disguised so nobody can assume its there on the /boot/efi unencrypted partition within the usb. With all that said, how can i get grub to use this keyfile to decrypt the boot partition at boot? (I saw a tutorial that demonstrates something similar to this om the arch wiki dm-crypt page, but its methods didn't work because they could be outdated?) Or is there a better method of securing my boot usb to be suggested? I even tried to just use veracrypt hidden volumes on linux with little success.