Instacart makes it easy to communicate with your shopper. When an item you want is out-of-stock at the store, your shopper will follow your replacement preferences.You can set item and delivery instructions in advance, as well as chat directly with your shopper while they shop and deliver your items. You can tell the shopper to:- Find Best Match: By default, your shopper will use their best judgement to pick a replacement for your item.- Pick Specific Replacement: You can pick a specific alternative for the shopper to purchase if your first choice is out-of-stock.- Don’t Replace: For items you’d rather not replace, choose “Don’t replace” to get a refund if the item is out of stock.You can update or cancel your order as long as your shopper hasn’t started shopping. If you need to make changes after shopping has started, you can use the app or website to approve replacements or chat with your shopper.