The seller is asking me to send him the receipt for the Colissimo International return shipping cost.That I paid for a refund via eBay How can I send the receipt to eBay Thank you for your help.Kind regards.

https://www.ebay.fr/help/buying/resolving-issues-sellers/contacter-un-vendeur?id=4021&st=3&pos=1&query=Contacter%20un%20vendeur&intent=contacter%20vendeur&lucenceai=lucenceai&docId=HELP1051#section1 "add photos" (under the text box) and you upload the file.