Fixture ID: noIban · XPath: /ubl:Invoice/cac:PaymentMeans/cac:PayeeFinancialAccount/cbc:ID
The payment means type code (BT-81) is "58", which means a credit transfer, so the payment account identifier (BT-84) must be present. You have told the buyer to transfer money without saying where to.
BR-61Set payment.iban to the receiving account (IBAN inside SEPA). Add payment.bic only if the account is outside SEPA or your bank requires it.
"payment": { "meansCode": "58", "iban": "DE02120300000000202051" }