Viewing & Changing Orders - Shopping Help - Apple - https://www.apple.com/shop/help/viewing_changing_orders - "Once an item is shipped or picked up, Apple will create an invoice for your order. To view or print your invoice, go to your Order Listing (Opens in a new window) page and select an item to go to the order details. Then, select View Invoice at the top of your order details page to access your invoice. If you need help viewing or printing your invoice, speak with an Apple Specialist at 1‑800‑MY‑APPLE."
Sometimes you need to be using the newest Safari to get some Apple features to work. If you cannot get it to work then usually a web browser will just have its own Print feature.