Examine source code of ncrandom

{
  "manifest_version": 2,
  "name": "ncrandom",
  "version": "1.3",
  "description": "Filter random questions from neetcode.io list by difficulty and questions solved, new or both",
  "content_scripts": [
    {
      "matches": [
        "*://*.neetcode.io/*"
      ],
      "js": [
        "dialog.js",
        "ncrandom.js"
      ]
    }
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_title": "Neetcode Random",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0a42c2f8-2f61-4ca5-b8bd-ab56c8a58079}"
    }
  }
}