Systemd-boot ALERT! /dev/mapper does not exist. Dropping to shell

I am running Ubuntu 22.10. I want to shift from GRUB2 to systemd-boot and I followed the following guides How to replace grub with bootloader "systemd-boot" in ubuntu 20.04? and Replace GRUB2 with systemd-boot on Ubuntu 18.04. However, when I boot using systemd-boot, I get the following error, Systemd-boot ALERT! /dev/mapper does not exist. Dropping to shell.

/etc/kernel/postinst.d/zz-update-systemd-boot

#!/bin/bash
#
# This is a simple kernel hook to populate the systemd-boot entries
# whenever kernels are added or removed.
#
       
# The UUID of your disk.
UUID="7c1b4f71-a3aa-4394-8c93-de5adf80d801"
#UUID="CHANGEME"
#UUID="205A-4B07"

# The LUKS volume slug you want to use, which will result in the
# partition being mounted to /dev/mapper/CHANGEME.
#VOLUME="CHANGEME"
VOLUME="/dev/nvme0n1p2"

# Any rootflags you wish to set.
#ROOTFLAGS="CHANGEME"    

# Our kernels.
KERNELS=()
FIND="find /boot -maxdepth 1 -name 'vmlinuz-*' -type f -print0 | sort -rz"
while IFS= read -r -u3 -d $'\0' LINE; do
    KERNEL=$(basename "${LINE}")
    KERNELS+=("${KERNEL:8}")
done 3< <(eval "${FIND}")

# There has to be at least one kernel.
if [ ${#KERNELS[@]} -lt 1 ]; then
    echo -e "\e[2msystemd-boot\e[0m \e[1;31mNo kernels found.\e[0m"
    exit 1
fi
       
# Perform a nuclear clean to ensure everything is always in perfect
# sync.
rm /boot/efi/loader/entries/*.conf
rm -rf /boot/efi/ubuntu
mkdir /boot/efi/ubuntu
      
# Copy the latest kernel files to a consistent place so we can keep
# using the same loader configuration.
LATEST="${KERNELS[@]:0:1}"
echo -e "\e[2msystemd-boot\e[0m \e[1;32m${LATEST}\e[0m"
for FILE in config initrd.img System.map vmlinuz; do
    cp "/boot/${FILE}-${LATEST}" "/boot/efi/ubuntu/${FILE}"
    cat << EOF > /boot/efi/loader/entries/ubuntu.conf
title   Ubuntu GNOME
linux   /ubuntu/vmlinuz
initrd  /ubuntu/initrd.img
options cryptdevice=UUID=${UUID}:${VOLUME} root=/dev/mapper/${VOLUME} ro rootflags=${ROOTFLAGS}
EOF
done
    
# Copy any legacy kernels over too, but maintain their version-based
# names to avoid collisions.
if [ ${#KERNELS[@]} -gt 1 ]; then
    LEGACY=("${KERNELS[@]:1}")
    for VERSION in "${LEGACY[@]}"; do
        echo -e "\e[2msystemd-boot\e[0m \e[1;32m${VERSION}\e[0m"
        for FILE in config initrd.img System.map vmlinuz; do
            cp "/boot/${FILE}-${VERSION}" "/boot/efi/ubuntu/${FILE}-${VERSION}"
            cat << EOF > /boot/efi/loader/entries/ubuntu-${VERSION}.conf
title   Ubuntu GNOME ${VERSION}
linux   /ubuntu/vmlinuz-${VERSION}
initrd  /ubuntu/initrd.img-${VERSION}
options cryptdevice=UUID=${UUID}:${VOLUME} root=/dev/mapper/${VOLUME} ro rootflags=${ROOTFLAGS}
EOF
        done
    done
fi

# Success!
exit 0

lsblk -f

nvme0n1                                                                              
├─nvme0n1p1 vfat     FAT32       205A-4B07                              41.2M    92% /boot/efi
├─nvme0n1p2 ext4     1.0         7c1b4f71-a3aa-4394-8c93-de5adf80d801    473M    92% /
└─nvme0n1p3 ext4     1.0         c859be11-26eb-43ec-b0eb-8be05c7cdde3   19.8G    90% /home

I then ran this command before following the rest of the guide

efibootmgr --disk /dev/nvme0n1p --part 1 --create --label "PreLoader" --loader /EFI/systemd/PreLoader.efi

Thank you.