Invoice copy for my order

Have you received an email that the order has shipped? The invoice is linked in tiny font size in the upper right of the "Your order has shipped" email.

We are other end users, not Apple, and can only answer based on our experience. My experience in ordering says the invoice is not generated until the order ships.

What is the customer email that i can write to

There is no email address like that. Near the bottom of your order confirmation email should be instructions for questions about the order. Example from an order I placed:

Contact Apple support with the order number at hand and see it they can provide a copy.

Are you working with an Apple retail store or a third-party service provider? One would think that an Apple Store or Apple Authorized Service Provider could work with the order number.

We are not Apple so cannot access an invoice copy on your behalf.