JUMP TOGetting StartedIntroductionIntegration TypesGet Started via APIGet Started via KlarnaAuthenticationRequest OAuth TokenpostValidate OAuth TokengetWebhooksAccepting OrdersCheckout WidgetCheckout ClientCheckout Session CreatepostCheckout Session ConfirmputBack-end Order CreationCreate OrderpostGet Legal FormsgetManaging OrdersOrdersOrder States & Decline ReasonsCancel OrderpostGet Order DetailsgetUpdate OrderpostInvoicesInvoice StatesGet InvoicegetCancel InvoicedeleteConfirm Invoice PaymentpostCreate Credit NotepostCreate InvoicepostExtend Invoice durationpostUpdate InvoicepostPlugins & SDKOverviewShopware IntegrationJTL IntegrationWooCommerce IntegrationSDK IntegrationIntegration via KlarnaKlarna Payments via APIKlarna Payments via ComputopKlarna Checkout IntegrationTestingSandbox TestingDocumentation for PSPsGet StartedMerchantsEnable your merchants to use BilliepostSessionsInitiate a widget checkout sessionpostInitiate a Payment Page checkout sessionpostConfirm AuthorizationpostOrdersCancel a confirmed AuthorizationpostCapture against an authorized OrderpostRefund a captured paymentpostUpdate order detailspostChargebacksRequest for informationDefend DisputeDispute ResultGet Legal Formsget https://paella-sandbox.billie.io/api/v2/legal-forms