On the checkout screen's search box, scan (or type) a barcode and press Enter. A barcode scanner types the digits then sends an Enter keystroke automatically, so Sprwt watches for that: on Enter, it checks whether the current search text matches any item's stored barcode. If it does, the search box clears and that meal opens — for a simple meal (one portion size, no add-ons) it's added straight to the cart; for a meal with multiple portion sizes or add-ons, the meal-prep screen opens instead so you can pick those before it's added. If the scanned text doesn't match any barcode, it just re-runs the normal name/barcode-substring search filter.