Barcode scannning on mobile website

I need to scan barcode on website by using camera on mobile, I found this:

https://github.com/andrastoth/WebCodeCamJS

then put it in free-host barmi123.cba.pl but if I try to open it on my mobile (Android 4.0, Google Chrome) something doesn't work ("scan area" is always black and nothing happens).

I copied all files from github (including index.html, I changed nothing) but there is section (at the bottom of the page) "Required HTML & Javascript example" should I use it?

I have no idea how to solve that problem(Is there any another solution - not webcodecamjs to scan barcode from website by mobile?(have to do it on website, not by application))