The app does not ask for ID. Handover is confirmed with your pickup code — that is the whole mechanism, and it is deliberately not a check on who you are.
Why a code rather than ID
Because it solves the problem better. A code proves you are the person the order belongs to, or somebody that person sent. It does not require a stranger to inspect your documents, and it does not require you to show a stranger your address.
It also means somebody else can collect for you without anything being bent — they bring the code. Can someone else collect it for me?
What a seller may reasonably ask
Your name, to match against the order. Normal, and it is on their screen.
The code. That is the one that matters.
Who you are collecting for, if you are not the buyer. Reasonable, and worth telling them in advance anyway so they are expecting somebody.
What they should not need
A document. No ID is required by the app, and a seller who insists on seeing one is going beyond what Metzee asks. Where it genuinely matters to them — a high-value piece, say — they should say so before you make the trip, not at the door.
A photograph of your ID sent in advance. Never necessary for a collection, and not something to send to a stranger. If anyone asks for a document image, that is worth reporting rather than complying with. How to report a seller or listing
Payment. The order is already paid. Can I check the item before paying at pickup?
The thing to protect
Your code, and only after you have the item. Only share it once you have the item in hand. is on the order for a reason — the code is what completes the handover, so it is your leverage while you check the item.
Do not send it ahead of arriving, and do not put it in a public chat.
If a seller refuses to hand over without ID
Do not argue at the door. Message them from the order, say the app uses the code, and ask them to confirm what they need before you come back.
If they still refuse and you cannot collect, report it from the order. A seller setting their own conditions beyond the agreed terms is something Metzee should know about, and your money is still protected while it is sorted.
For a seller reading this
Someone arriving with the right code is the normal case, including when it is not the buyer — people send a driver, a relative, a colleague. Confirm the code, hand it over, mark it collected.
Somebody with no code is the case to refuse. That is what the code is for.
More: how to collect an order, how pickup works, where exactly do I collect from.