how can i get a receipt from walmart for item i picked up

They don't give reciepts. You have to use the label on the box/package.

If you ordered the item and picked it up, yes. If paid by credit card or debit card, yes. If neither of the above and paid with cash, no.

If u used debit card, they can print receipt from customer service desk.

You may be able to get it online. Call the store. They can tell you.