Thanks for trying out Visa B2B Virtual Accounts payment method APIs.
Please allow us few more days to get back to you with the correct field name.
Appologies for the inconvinience caused.
Please use "cardAccountExpiryDate" as the correct field name.
Until we re-visit our documentation and correct where necessary, you may refer the sample (swagger) request payload field names as it contains the correct names in it.
Once again apologies for the inconvenience caused and thank you for highlighting this.