Creates a ZUGFeRD 2.x hybrid PDF/A-3 from structured JSON. The default (and recommended) profile is EN 16931; a `specificationId` declaring an official Factur-X/ZUGFeRD profile URN selects that profile instead. For the header-only booking-aid profiles (MINIMUM, BASIC WL) the embedded XML carries the profile's header subset while the rendered PDF, which is the legal invoice for those profiles, shows the full line data; line items therefore remain required input. Declaring the XRechnung 3.0 URN selects the XRECHNUNG reference profile (ZUGFeRD 2.2+): the embedded XML is an XRechnung in CII syntax, attached as `xrechnung.xml` and validated against the German CIUS rules, so the XRechnung requirements apply (Leitweg-ID in `buyerReference`, seller contact, electronic addresses).

Example request

{
  "invoice": {
    "invoiceNumber": "INV-2026-00045",
    "issueDate": "2026-05-17",
    "currency": "EUR",
    "seller": {
      "name": "Acme Engineering GmbH",
      "vatIdentifier": "DE123456789",
      "legalRegistration": "HRB 12345",
      "postalAddress": {
        "line1": "Hauptstraße 12",
        "city": "Berlin",
        "postCode": "10115",
        "country": "DE"
      }
    },
    "buyer": {
      "name": "Globex SAS",
      "postalAddress": {
        "line1": "15 rue de Rivoli",
        "city": "Paris",
        "postCode": "75001",
        "country": "FR"
      }
    },
    "paymentDetails": {
      "paymentAccountIdentifier": "DE89370400440532013000"
    },
    "lines": [
      {
        "quantity": 10,
        "priceDetails": {
          "netPrice": 150
        },
        "vatInformation": {
          "rate": 19
        },
        "item": {
          "name": "Senior consulting"
        }
      }
    ]
  },
  "options": {
    "language": "EN",
    "brandColor": "#0F766E"
  }
}