Cancels an existing order.
For orders with recurring payments, a cancellation can be set to occur either IMMEDIATELY or at the NEXT_PAYMENT_DATE.
For orders with one-time payments, a cancellation can only be set for IMMEDIATELY.
When a buyer cancels their order during the free trial period, the buyer's subscription expires at the end of the free trial period and they will not be billed. The buyer may continue using the benefits until the end of the free trial period.
When a Wix user cancels an ordered plan during the free trial period, they choose whether to apply the cancellation
IMMEDIATELY or at the NEXT_PAYMENT_DATE. Canceling IMMEDIATELY will end the subscription for the buyer
immediately, even during the free trial period and the buyer won't be billed. Canceling at the
NEXT_PAYMENT_DATE allows the buyer to continue using the benefits of the subscription until the end of the free trial period.
Then, the subscription ends and the buyer is not billed.
You can only call this method when authenticated as a Wix app or Wix user identity.