Webhook

During registration the Merchant may provide endpoint that will accept POST payload to utilize webhooks that will contain the status of the order.

Webhook is executed in following scenarios:

Checkout is accepted and order is created (state: approved) - note that without 'approved' status, the /charge is not possible. This webhoook will be sent only if immediate_capture is disabled.
Order is charged (state: completed). This webhoook will be sent only if immediate_capture is enabled or for Pay in 3.
The customer is rejected on scoring (state: cancelled)
Scoring failed - unknown error (state: error)
Settled - Twisto has transfered funds (settled_date: <date>)
Refunded - order is refunded (refunded_amount: <Decimal>)
Cancel - order is canceled (state: cancelled)

The webhook will look like this:

{
    "checkout_id": ...,
    "total_amount": ...,
    "refunded_amount": ...,
    "created_date": "2019-08-24T14:15:22Z",
    "settled_date": "2019-08-26T14:15:22Z",
    "type": "standard",  # standard
    "state": "approved", # approved (scoring accepted), cancelled (scoring rejected or cancelled by merchant), error
    "external_id": ... # merchant transaction id
}