put https://api.reepay.com/v1/subscription//preview
A subscription change can be tried out by creating a subscription change preview. The preview does not perform any actual change but sums up what would happen if the change request was performed.
Returns a ChangedSubscription object which is the Subscription object after the change with additional parameter SubscriptionChangeJournal describing potential compensation and new billing.
Errors
The operation can generate the same errors as for a normal change operation.