Works out an order's lines, totals and payment schedule without saving anything. No order is created and no ID is issued.

Send the same body as Create order. The figures are what the order will charge if you create it with that body. customer_id is optional here.

• Tax is included in the price, not added on top.
• schedule_preview lists the scheduled payments. It's empty for single payment and metered orders.
• The response has no id, invoice_id, status or payment totals, because nothing is saved.

Use the preview's figures when you update an order. The update saves the amounts you send as they are.