We know it's common for European companies to send invoices for all business purchases.
As a US-based company we do not generate invoices. And, you should not be obligated to present an invoice from us!
You should be able to pull a copy of your receipt from your email, if you paid with a credit card or from PayPal.
If you can't find a copy of your receipt, please reach out to our customer service team and we can resend it. For fastest results, it helps to have your order number, the email address you used for the purchase, and/or the date of your transaction!