Create a New Disk in Packer Linux

Packer
1

Good afternoon,
I am pretty sure this is a simple task. We have an existing ova file ( 20 Gbyte /dev/sda ) we are converting to a vmx and then trying to add an extra Hard Disk too ( 120 Gbyte /dev/sdb )
Using this packer.hcl file it never creates the /dev/sdb ( and pretty sure its missing more parameters )

variable "hostname" {
  type    = string
}
variable "ssh_username" {
  type    = string
}
variable "ssh_password" {
  type      = string
  sensitive = true
}
variable "vmware_source_path" {
  type    = string
}
variable "disk_additional_size_mb" {
  type    = list(number)
  default = [102400]
}
locals {
  vm_name    = "vmware-${formatdate("YYYY-MM-DD-hh-mm-ss", timestamp())}"
  output_directory  = "./builds/vmx"
}


source "vmware-vmx" "ubuntu1804" {
  headless         = true
  output_directory = local.output_directory
  shutdown_command = "sudo -S shutdown -P now"
  source_path      = var.vmware_source_path
  ssh_password     = var.ssh_password
  ssh_port         = 22
  ssh_username     = var.ssh_username
  vm_name          = local.vm_name
  format           = "ova"
  ovftool_options  = [ "--shaAlgorithm=SHA1" ]
  disk_additional_size = var.disk_additional_size_mb
  vmx_data_post    = {
    "memsize": "8192"
    "numvcpus": "4"
  }  
}

build {
  sources = ["sources.vmware-vmx.ubuntu1804"]

  provisioner "ansible" {
    playbook_file        = "../ansible/playbook.yml"
    inventory_directory  = "../ansible/inventory/"
    ansible_env_vars     = ["ANSIBLE_CONFIG=./ansible.cfg"]
    galaxy_file          = "../ansible/ansible-requirements.yml"
    galaxy_force_install = true
    use_proxy            = true
    groups               = ["hosts"]
    host_alias           = var.hostname
    user                 = var.ssh_username
  }

  post-processor "shell-local" {
    environment_vars = [
        "OVA=${local.output_directory}/${local.vm_name}.ova", 
    ]
    script           = "./set_empty_ova_properties.sh"
  }
}