curl --request POST \
  --url https://api.iotools.cloud/v1/tool/number-to-words \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "number": "0",
  "format": "cardinal",
  "currency": "usd",
  "capitalize": "true"
}
'

{
  "tool": "number-to-words",
  "tool_version": "1.0.1",
  "outputs": {
    "outputWords": "Zero"
  },
  "credits_used": 3,
  "credits_remaining": null
}