(The hard-way - But it is one time setup, which will turn on automatically when you open OBS.)
If you're using Windows, see here how add extra parameters. Commands bellow are only for Linux.
$ cd /usr/share/applications/
$ ls | grep obs
# pick the name that you see here. For me, it's `com.obsproject.Studio.desktop`
$ sudo vi com.obsproject.Studio.desktop
# find the line `Exec=`, modify it into the line below
# Exec=obs --enable-gpu --enable-media-stream
#
# press : and "x", then press Enter to escape Vi editor
Open terminal/Window prompt
$ cd /path/to/greencam
$ npm install
NPM is a package manager of NodeJS programming runtime. If you don't have both NodeJS and NPM, please follow the link here (Linux | Windows) to install NodeJS first. NPM is shipped with NodeJS.
And start the web tool locally
$ npm start
In the URL, input http://localhost:3000
To make sure the web tool worked, you can access this URL from Google Chrome and play with it.
close the dialog and DONE!!