This one works in hybrid mobile: https://appstore.home.mendix.com/link/app/1469/Mendix/Barcode-Scanner
It will not work in native mobile. To my knowledge there is none yet for native mobile.
Regards,
Ronald
Currently for the webcam there are none yet. I did found this Javascript: https://ourcodeworld.com/articles/read/460/how-to-create-a-live-barcode-scanner-using-the-webcam-in-javascript But you would need to transform that into a widget.