Are you enrolled in eBay's Global Shipping Programme?
There's no postage price and method to Ukraine showing on your listings and if you are enrolled in the GSP you won't be able to send an invoice.
You'll need to cancel the orders and then relist them all in one Buy It Now listing with your own postage price and postage method to Ukraine, then your buyer can re-purchase.
Due to the troubling events in Ukraine, couriers have suspended delivery services to areas of Ukraine and Russia. As a result, eBay has suspended all exports into Ukraine and Russia, including the Global Shipping Programme Service.
There are currently limited shipping options for sellers to fulfill sales to Ukraine and Russia, and buyers in Ukraine and Russia may be unable to purchase items on eBay until stable shipping services resume.
