PaymentRequest.shippingOption - Web APIs
syntax // returns the id of the selected paymentshippingoption var shippingoption = request.shippingoption; example in the example below, the paymentrequest.onshippingoptionchange and the paymentrequest.onshippingaoptionchange events are dispatched.

PaymentResponse.shippingOption - Web APIs
syntax var shippingoption = paymentrequest.shippingoption; example in the example below, the paymentrequest.onshippingaoptionchange event is called.