You cannot add international shipping to any of listed auctions, as they all have bids.
For future listings, if you wish to sell internationally you need to show this in your Site Preferences on your homepage here:
https://www.ebay.co.uk/ship/prf
On the left sidebar select Postage Preferences, scroll down to Exclude Postage locations and select the countries there you do and do not wish to post to. There is a little box at the bottom of that list to add this to any item listed , with no bids.
Be aware, if you are a new seller, or one returning after a long break, you may not be able to sell internationally straight away.
