22-01-2021 11:25 PM
On My eBay click on More Actions > Send Payment Details, far right of item on your sold page. Or on seller hub go to Orders, select the item and select Send Invoice from the drop-down menu. Change the postage and click on Send Invoice.
But do you know why they need an invoice? eg. if they cannot pay via ebay due to incorrect email address sending an invoice won't help.