JS module webcam.js not working in (--app) mode

Describe the problem I have used webcam.js in the html's JS section of the 'web' directory which takes photos from webcam and save it in the assets folder..This is working perfectly fine in the localhost mode as expected (in browser) but when used in the app mode (using --app in cmd line) , webcam.js is unable to work i.e it never starts on clicking the button....Why the JS module 'webcam.js(https://github.com/jhuckaby/webcamjs)' is not working in APP mode ??

Desktop (please complete the following information):

• OS: - MacOs
• Browser - Chrome (in --app mode)
• Version - The recent one