How to determine which subscription an order belongs to?

It looks like the Retrieve an Order (https://developer.infusionsoft.com/docs/rest/#!/E-Commerce/getOrderUsingGET) endpoint doesn’t include a subscription ID, nor does the List Subscriptions endpoint (https://developer.infusionsoft.com/docs/rest/#!/E-Commerce/listSubscriptionsUsingGET) include orders in the response. Linking orders to subscriptions is pretty important for using Infusionsoft to bill subscriptions. Is there any way to do that with the API? Thanks

Are you asking if you can specify a subscription when creating an order? If so, we don’t support that. We only support creating a subscription via the API that we will then create orders from automatically.

No, I was actually looking for a way to query orders that belong to a given subscription, or vice versa. Yesterday I was advised by a support agent that this is only possible with the legacy API data service.