We released a change to the Invoices API in beta today - the introduction of invoice delivery method and automatic payment source! As part of these changes, we have deprecated the request_method field on the InvoicePaymentRequest object.
It has been replaced with delivery_method on the Invoice object, and automatic_payment_source on the InvoicePaymentRequest object. These changes will allow you to specify how to send and automatically charge invoices.
If you do not upgrade to the new API version, everything will continue to work as before.
When you do upgrade to the new API version, some code changes may be required.
For more information, please see the notes on this migration specified in our overview page:
Feel free to ask questions or provide feedback here in the forums!