Check your order details, and perhaps do so on a PC / laptop and not the app, if it's not there, you must contact eBay Customer Services for this code. The store will not give you the code without it, and you have 7 days from being notified that it's in store, for you to pick up the item. The store can dispose of the item as they wish, after that time lapses.
Customer Services is open now, until 6 p.m. to night being a weekend.
To Contact Customer Services, I find the quickest way to contact them, either for a Live Chat, or you can select to speak and request a Call Back, to click on this link:
https://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
On weekdays lines open between 8 a.m. and 10 p.m.
On weekends they open between 9 a.m. and 6 p.m.
