Why is a payment receipt not enough when Skydo asks for an invoice?

A payment receipt shows a transfer or payment event. An invoice describes what you sold, who you billed, and how much was due. They serve different purposes, so provide the actual invoice when Skydo asks for it.

Use the invoice already issued to the client or create the proper invoice for the sale. Check the invoice number, date, business and client details, clear description, amount, currency, and relevant classification details. Keep the payment receipt as supporting evidence rather than replacing the invoice with it. If you cannot provide the original invoice or the documents do not match, explain the issue to support before submitting a different document as a substitute.