Non-English Character cause vm build failure

I have the packer template which contains the Russian characters, e.g.
Администратор, the vm can’t be built, How should I handle the speical characters?

{
  "variables": {
    "iso_url": "",
    "vm_name": "",
    "user_name":"", 
    "password":""
  },
  "builders": [
    {
      "type": "hyperv-iso",

      "iso_url": "{{user `iso_url`}}",
      "iso_checksum": "none",
      "temp_path": ".\\",
      
      "use_fixed_vhd_format": true, 
      "skip_compaction": true,
      "differencing_disk": false,

      "shutdown_command": "shutdown /s /t 0",
      "shutdown_timeout": "1h",

      "vm_name": "Администратор",
      "memory": 4096,
      "cpus": "2",
      "switch_name": "Nova",

      "generation": 1,
      "communicator": "winrm",
      "winrm_username": "Администратор",
      "winrm_password": "{{user `password`}}",
      "winrm_timeout": "1h",
      "output_directory": ".\\output"
    }
  ],
  "provisioners": [
    {
      "type": "windows-update",
      "search_criteria": "AutoSelectOnWebSites=1 and IsInstalled=0"
    }
  ]
}