curl --request GET \
  --url https://api.e-invoice.be/api/outbox/ \
  --header 'Authorization: Bearer <token>'

{
  "items": [
    {
      "id": "<string>",
      "created_at": "2023-11-07T05:31:56Z",
      "document_type": "INVOICE",
      "state": "DRAFT",
      "direction": "OUTBOUND",
      "customer_name": "<string>",
      "customer_id": "<string>",
      "customer_email": "<string>",
      "purchase_order": "<string>",
      "invoice_id": "<string>",
      "invoice_date": "2023-12-25",
      "due_date": "2023-12-25",
      "note": "<string>",
      "vendor_name": "<string>",
      "vendor_email": "<string>",
      "vendor_address": "<string>",
      "vendor_address_recipient": "<string>",
      "customer_address": "<string>",
      "customer_address_recipient": "<string>",
      "billing_address": "<string>",
      "billing_address_recipient": "<string>",
      "shipping_address": "<string>",
      "shipping_address_recipient": "<string>",
      "currency": "EUR",
      "tax_code": "S",
      "vatex": "VATEX-EU-79-C",
      "vatex_note": "<string>",
      "subtotal": "<string>",
      "total_discount": "<string>",
      "total_tax": "<string>",
      "invoice_total": "<string>",
      "amount_due": "<string>",
      "remittance_address": "<string>",
      "remittance_address_recipient": "<string>",
      "service_address": "<string>",
      "service_address_recipient": "<string>",
      "service_start_date": "2023-12-25",
      "service_end_date": "2023-12-25",
      "vendor_tax_id": "BE1018265814",
      "vendor_company_id": "1018265814",
      "customer_tax_id": "BE1018265814",
      "customer_company_id": "1018265814",
      "payment_term": "<string>",
      "payment_details": [
        {
          "iban": "<string>",
          "swift": "<string>",
          "bank_account_number": "<string>",
          "payment_reference": "<string>"
        }
      ],
      "tax_details": [
        {
          "amount": "<string>",
          "rate": "<string>"
        }
      ],
      "items": [
        {
          "amount": "<string>",
          "date": "<unknown>",
          "description": "<string>",
          "quantity": "<string>",
          "product_code": "<string>",
          "tax": "<string>",
          "tax_rate": "21.00",
          "unit": "10",
          "unit_price": "<string>",
          "allowances": [
            {
              "reason": "<string>",
              "reason_code": "41",
              "multiplier_factor": "<string>",
              "amount": "<string>",
              "base_amount": "<string>",
              "tax_rate": 21,
              "tax_code": "S"
            }
          ],
          "charges": [
            {
              "reason": "<string>",
              "reason_code": "AA",
              "multiplier_factor": "<string>",
              "amount": "<string>",
              "base_amount": "<string>",
              "tax_rate": "21.00",
              "tax_code": "S"
            }
          ]
        }
      ],
      "attachments": [
        {
          "file_name": "<string>",
          "id": "<string>",
          "file_type": "application/pdf",
          "file_size": 0,
          "file_url": "<string>"
        }
      ],
      "allowances": [
        {
          "reason": "<string>",
          "reason_code": "41",
          "multiplier_factor": "<string>",
          "amount": "<string>",
          "base_amount": "<string>",
          "tax_rate": 21,
          "tax_code": "S"
        }
      ],
      "charges": [
        {
          "reason": "<string>",
          "reason_code": "AA",
          "multiplier_factor": "<string>",
          "amount": "<string>",
          "base_amount": "<string>",
          "tax_rate": "21.00",
          "tax_code": "S"
        }
      ]
    }
  ],
  "total": 123,
  "page": 123,
  "page_size": 123,
  "pages": 123,
  "has_next_page": true
}