curl -X POST https://api.example.com/invoices \
  -H 'Authorization: Bearer <token>' \
  -H 'Content-Type: application/json' \
  -d '{
    "tenant": "acme-platform",
    "amount": 129.90,
    "currency": "EUR",
    "customer": {"vatNumber": "FRxxxxxxxxx"},
    "lines": [...]
  }'