Is your item above £135?
If so, you'll be expected to pay Customs Duty this end, plus the courier admin fee. If you don't and it's returned to the sender, eBay will not offer buyer protection/money back guarantee and you can't get a refund via eBay.
If your previous purchases from international sellers were below £135 then you will have paid the import fee at eBay checkout (they collect it and pass it on to HMRC).
Or, if your previous purchase you weren't charged on was pre-Brexit and from an EU country then there would have been import fees at all.