How can you add bank account on a payment request generated from a refund in Receivables?

What are the steps to update an installment on a payment request generated from a refund in Receivables? We have scenarioes where payment requests are created without a bank accounts. After we create the bank account on the customer, we are still unable to search for and add the new bank account on the payment request in payables.

Please elaborate on any steps, processes etc that needs to be run in order to update the payment request.

Thanks