Printing and Scanning in Angular 6

The biggest issue here is that you need to install something on the client side because the browser cannot access the scanner directly.

There is an OCX-based solution, which needs to be installed on the client side.

The downside of the OCX, it is only supported by some and not all versions of IE, and almost no other browsers.
A more general approach installs a self-hosted service at the client side that communicates with the browser and your web-based application.
LEADTOOLS offers a solution, which is this:
https://www.leadtools.com/help/leadtools/v20/dh/to/web-scanning-framework.html

The WebScanning feature can work on Windows and Linux clients’ side. In addition, you can check their online demo here:
https://demo.leadtools.com/javascript/ScanningDemo/