I'm trying to get shipping rates information to allow shop owners to select a shipping method/rate from a custom draft order form. Basically, I want to be able to show the same rates to select from the shipping line popup in the admin checkout form when creating an order. I know I can fetch shipping rates for a cart on the storefront as a customer if I call `/cart/shipping_rates.json` with the shipping address information in the query parameters. Is there a similar way I can fetch the information for a draft order in the admin panel? The list of shipping rates must come from somewhere, but I haven't been able to figure it out yet. It seems like the `CarrierService` API *might* be the way to do it, but that API is only available on the Advanced plans for $299/mo, and I just need it to test my embedded app, not to actually sell anything myself.
Second this. The introductory paragraph in the Draft Orders API documentation states: "Using the Draft Orders API, you can create orders on which shipping, taxes and all total amounts are calculated by Shopify.", however there does not appear to be any way to get shipping rates calculated by Shopify.