How to get a receipt for an iPhone 17 Pro Max?

The invoice information for retail and online stores is at:

Viewing & Changing Orders - Shopping Help - Apple

View or Print Invoice

"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 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.

Ordered it from where?

If you ordered it from Apple, you should get all the documentation you need in your email.