Invoice is not the right word, still, they should provide it. All the other vendors (Google, Microsoft, etc) do so. It's not actually an invoice but a Payment Receipt (because, as others have noted, an invoice would go in the opposite direction). Still, a recept like this should have mostly the same data, details of Apple as a business entity, details of the developer (as a business entity), EU VAT numbers where applicable, date, amount, some receipt ID, and so on.
djgtram
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