I’ve used RS232 serial barcode scanners for many years. Manufactures can provide different interface cables depending on your needs, such as USB or RS232. If the barcode is in the same position on the product, you can setup a fixed mount scanner to read continually. It will transmit the code as soon as it reads it. If the position of the barcode is not known, you’ll need a wide-field imaging scanner or even a scanning tunnel to scan every side of the package (which can get very expensive).
Note that RS232 distance is limited. I try not to exceed 30 feet at 9600 baud.