curl --request GET \
  --url https://api.docsautomator.co/listPlaceholdersV2 \
  --header 'Authorization: Bearer <token>'

{
  "placeholders": {
    "main": [
      "customer_name",
      "invoice_date",
      "total"
    ],
    "line_items_1": [
      "description",
      "quantity",
      "rate",
      "amount"
    ]
  }
}