Two things to be aware of here.
If they send a courier, they void all buyer protection, as they sent a third party, so they cannot later open a case for item not as described.
More importantly, you need to send the buyer a message that the courier Must bring with them the 6 digit QR collection code which they, the buyer, would have received after payment was made for the item. Make it very clear you will not release the item without this code.
I would also scan / enter those numbers of that code alongside... Confirm Collection in the order details, in the presence of the courier, make sure the code works. If it doesn't again, do not release the item.
Should the code not work you cancel the order citing Problem with Buyer's Address. This refunds the buyer and your seller performance is not affected.
I cannot stress strongly enough no code = no item !
@salsasaltiger
