This barcode scanner uses the Webcam on your PC and is based on Qt and GStreamer. It may also works on Windows (untested).
It can also automatically look up the products for the scanned EAN and UPC barcodes online on https://www.ean-search.org/ .
Open a terminal window:
sudo apt install build-essential git qtbase5-dev libgstreamer1.0-dev \
libgstreamer-plugins-base1.0-dev gstreamer1.0-plugins-base \
gstreamer1.0-plugins-good gstreamer1.0-plugins-bad
git clone https://github.com/eansearch/BarcodeScanner
cd BarcodeScanner
qmake
makeThen start it with
./BarcodeScanner &