channel: Slug of a channel in which to create checkout.
shippingAddress: the shipping address (if needed).
billingAddress: the billing address.
items: a list of checkout items (products), each item contains the product ID, a product variant ID and its quantity.
id: a unique checkout ID.
totalPrice: the total price of the checkout items and shipping costs.
availableShippingMethods: a list of available shipping methods for this checkout. If the items in the cart require shipment.
availablePaymentGateways: a list of payment gateways that are currently configured on your partner Outshifter account and can be used to pay for the checkout. Only gateways which support the checkout currency are returned. For each gateway, API returns an ID, a name, and a config object, which for some gateways may return additional information required to process the payment in the frontend.
Checkout.availablePaymentGatewaysfield. Depending on the chosen gateway, you may need additional configuration.