I'm helping a client migrate data to Shopify using the Admin API. I need to create historical orders, but I've noticed that after creating each order, the Shopify admin backstage generates a new customer entry, even if the profile for that customer already exists with the same email. The backstage ends up showing two customer profiles with the same name and email.
I have tried including the pre-built customer's email in the order.customer.email and order.email parameters, but it doesn't work. The orders cannot be associated with the same customer. I would like to know if this behavior is intended by design or if there are additional parameters I should include to correctly associate the "new" order (new to Shopify, but historical for my client) with the customer profile. Any help is greatly appreciated. Thank you!