Mender-convert unsupported script state: Download

I am trying add a state script that keeps our battery powered IOT devices powered up for an extended period while downloading the large A/B update image. I am trying to hook into the Download_Enter state and I modified the config file adding the script line like this:

source configs/beaglebone_black_base_config
mender_create_artifact() {
    local -r device_types="${1}"
    local -r artifact_name="${2}"
    local -r image_name="${3}"
    local -r all_device_types="$(for device_type in $device_types; do echo " --device-type $device_type"; done)"

    log_info "Writing Mender artifact to: ${mender_artifact}"
    log_info "This can take up to 20 minutes depending on which compression method is used"

    run_and_log_cmd "mender-artifact --compression ${MENDER_ARTIFACT_COMPRESSION} \
      write rootfs-image \
      --file work/rootfs.img \
      --output-path ${mender_artifact} \
      --artifact-name ${artifact_name} \
      --script Download_Enter_00_keepalive \

I am getting an unsupported script state error like this:

	mender-artifact --compression gzip       write rootfs-image       --file work/rootfs.img       --output-path deploy/IMG07-beaglebone-emmc-mender.mender       --artifact-name release-16       --script Download_Enter_00_keepalive        --device-type beaglebone-emmc
	Unsupported script state: Download

What could be the problem? Thank you

As explained in the root filesystem and artifact scripts section of the state-scripts documentation, scripts that have the Artifact prefix can be managed via mender-artifact and others like Download must be in the currently running image in order to be executed during the installation of the artifact you’re creating (and so must exist inside of the artifact you’re creating if you also want them to be available to the next update, and so on).