How do I download proof of purchase

Hi luvable1990,

If you are sure don't have a paper receipt:

(some people keep their paperwork in the original packaging ?)

Apple often e-mail a receipt to you when you make a purchase.

You might want to search through your Apple e-mails for it.

or

you can try this Support article:

See your purchase history for the App Store, iTunes Store, and more

https://support.apple.com/en-us/HT204088

Hope this helps you :)