curl --request GET \
  --url https://api.heffl.com/api/v2/document-templates/{id} \
  --header 'x-api-key: <api-key>'

{
  "id": "<string>",
  "name": "<string>",
  "type": "<string>",
  "isActive": true,
  "isSignatureRequired": true,
  "customFields": [
    {
      "key": "<string>",
      "label": "<string>",
      "dataType": "<string>",
      "required": true,
      "values": [
        "<string>"
      ]
    }
  ],
  "documentName": "<string>",
  "subject": "<string>"
}