Hi Samrat,
In the images below I have an example of a working barcode scanner.
Some important things:
The scanned result need to be written to an attribute (unlimited string) in your database, therefore also check the write access.
In the microflow I can use the content of the barcode in Retour.Barcode
You have to provide the optical feedback yourself, for example with a show message or a close page.
Hope it helps!