Packer manifest missing "OSDiskUriReadOnlySas" artifact

I have some packer code to generate a VHD from an Azure Marketplace image. The result produces a OSDiskUriReadOnlySas that I can’t see in the manifest.

Packer Output:

OSType: Windows
StorageAccountLocation: australiaeast
OSDiskUri: https://<storage_account>.blob.core.windows.net/<container>/Microsoft.Compute/Images/<folder>/windows_server2019-osDisk.25d65d12-f827-45af-a37e-6b361ea2d380.vhd
OSDiskUriReadOnlySas: https://<storage_account>.blob.core.windows.net/<container>/Microsoft.Compute/Images/<folder>/windows_server2019-osDisk.25d65d12-f827-45af-a37e-6b361ea2d380.vhd?se=2022-10-26T21%3A12%3fghfghrtyh45%$45y7DBrTtDNmVIB5YZ7SUESheShmTGGYfAWm9c%3D&sp=r&sr=b&sv=2018-03-28
TemplateUri: https://<storage_account>.blob.core.windows.net/<container>/Microsoft.Compute/Images/<folder>/windows_server2019-vmTemplate.25d65d12-f827-45af-a37e-6b361ea2d380.json
TemplateUriReadOnlySas: https://<storage_account>.blob.core.windows.net/<container>/Microsoft.Compute/Images/<folder>/windows_server2019-vmTemplate.25d65d12-f827-45af-a37e-6b361ea2d380.json?se=2022-10-26T21%3A12%3A00Z&sig=z7WEFGEGE#FW@QWWHiFYJS0lqsGIM%3D&sp=r&sr=b&sv=2018-03-28

And I have some code to output the manifest:

  post-processor "manifest" {
    output     = "server2019_manifest_${uuidv4()}.json"
    strip_path = true
  }

The manifest is missing OSDiskUriReadOnlySas:

"builds": [
    {
      "name": "server_2019_vhd",
      "builder_type": "azure-arm",
      "build_time": 1664226720,
      "files": null,
      "artifact_id": "https://<storage_account>.blob.core.windows.net/<container>/Microsoft.Compute/Images/<folder>/windows_server2019-osDisk.25d65d12-f827-45af-a37e-6b361ea2d380.vhd",
      "packer_run_uuid": "20d6c483-e9eb-493b-b729-e9a4987916f4",
      "custom_data": null
    }
  ],
  "last_run_uuid": "20d6c483-e9eb-493b-b729-e9a4987913f4"
  }
]

How can I get OSDiskUriReadOnlySas in the manifest?