Order Processing Channel

Specifies the sales channel through which the shopper provides their card details. Currently, the value can only be sent for WorldPay. For other processors, ecommerce is used by default.

Possible values:
ecommerce - Internet or electronic commerce transaction.
moto - Single mail or telephone order transaction.

Currently this is only allowed for WorldPay Merchants

This is an optional field in the Invoice Object, if null or left blank it will take default set in Merchant Settings for Worldpay Merchant

  "invoice": {
    "merchantInvoiceRefId": "123456789",
    "orderProcessingChannel": "moto",
    "amount": {
      "currency": "USD",
      "value": 30.99
    }
  },

Default is set in Merchant Settings -> Merchant Details