Promise resolving to an object with the subscriptionID of the newly created subscription. When successfully called, the subscriptions
object will also be updated by calling getSubscriptionDetails(subscriptionID)
with the newly created subscriptionID
{
"subscriptionID": 88 // newly created subscription ID.
}
See documentation for corresponding error codes:
https://redirector.arcpublishing.com/alc/docs/swagger/?url=./arc-products/arc-sales.json#/Subscription_Interaction/redeemGiftSubscription