11-02-2021 10:39 PM
Ebay policy says
If this eCP number is missing, your parcel will be rejected at the eBay collection point location. In this case, your parcel will be unidentifiable and may be disposed of, without reimbursement. This may cause an ‘Item not received’ case to be raised against you by the buyer.
You can read the whole Click and Collect policy on this link
https://www.ebay.co.uk/help/selling/posting-items/setting-postage-options/click-collect?id=4180