Could it be device or browser trouble? Many thing are problematic on the app or mobile browser, if using switch to the more reliable laptop / PC and Chrome that combo seems to work best..
If this still doesn't work Contact eBay Customer Services, to hep you with this as you do have a small window to return that item. They should be able to provide that label for you.
This is the easiest and quickest way to contact eBay Customer Services, for a Call Back option.
https://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
Lines open 8 a.m. - 10 p.m. on weekdays
9 a.m. - 6 p.m. on weekends.
Automated agents will be available on chat outside of the above hours.
I do recommend contacting CS very first thing in the morning, when the lines first open, as there's more chance of Dublin answering.
@pabretel
