Need purchase invoices for iPad with forgotten passwords

You need to understand that the Apple Support Community is a user-to-user technical forum. Contributors here are all end-users, just like you. Forum Contributors have no means by which to access any information concerning your purchase transactions.

Other than the site Moderators, Apple neither monitors nor participates here. As such, if you hope to reach Apple through these forums, you will be sadly disappointed.

Should you choose to do so, you might attempt to seek assistance directly from Apple Support. You can contact the Support Team using the Support link at top-right or bottom-left of this page.

If you purchased directly from Apple, either in one of their Apple-owned retail shops or from the Apple online store, an invoice may be available in your Apple Account (account.apple.com) for about 18 months for time of purchase. If longer than that, you will probably not be able to get an invoice copy.

If you purchased from any other seller including an Apple-authorized reseller, you must work with the reseller because Apple will not have another company's invoice.

we are not apple

these forums are user helping other users like yourself, it's sort of going to a physical apple store and asking other customers their advice

if you can't remember the passcode read How to reset your iPad passcode using your Mac or PC - Apple Support

if you can't remember the apple account password If you forgot your Apple Account password - Apple Support

about invoices read Purchase invoice - Apple Community