There are T & C's to be able to add Click & Collection to your item:
eBay will automatically offer Click & Collect on your listings if:
Your item is over £5
You're offering a quick dispatch time (0-3 days is ideal)
Your item weighs no more than 15kg (including packaging) and no one side of the parcel exceeds 90cm, with max dimensions of 0.324 cubic metres. (Any items that are too large or exceed the weight limit will be rejected on arrival at the Click & Collect location and may be disposed of, without reimbursement)
Your item isn't classified as dangerous or age-restricted
Please see the guidance here:
https://www.ebay.co.uk/help/selling/posting-items/setting-postage-options/click-collect?id=4180&st=1...
Even if it has been applied to your listing it may not be available to your buyer, it depends where they live and if there's a Click & Collect store local to them.
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