From the information link you provided: 

• For sellers where eBay collects EU VAT on the transaction under OSS or IOSS rules, eBay will issue sellers with either a transaction document (imports) or a self-billing invoice (valid VAT registration number on file, with goods sold from within the EU) as appropriate
  This document will show details of the transaction for which eBay has taken on VAT responsibility, and can be used for the seller's own records as evidence that eBay has collected VAT.

Where is the "transaction doument" please??