What a Squarespace order writes
One invoice per order, in draft, in your currency.
Each Squarespace order becomes one draft invoice in Xero: the buyer matched or created as a contact by name and email, one line per item at the price actually paid, and the order’s own currency. It lands as a draft so you approve it in Xero the way you approve anything else; nothing is posted to your accounts behind your back.
Squarespace tells us the moment an order is placed, so the draft invoice is in Xero a second or so later; it is only Squarespace’s stock edits that wait for our two-minute check. Cancel the order before you approve the invoice and the draft is removed. Anything you have already approved is yours to credit in Xero.