Examine source code of Webpage to Video

{
  "manifest_version": 3,
  "name": "Webpage to Video",
  "description": "Converts web pages or local HTML files you are currently looking at into videos. The videos are produced in the mp4 (H264) format.",
  "version": "1.2.1",
  "options_page": "options.html",
  "browser_specific_settings": {
    "gecko": {
      "id": "webpagetovideo@grabz.it"
    }
  },
  "action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "host_permissions": [
    "*://grabz.it/*",
    "file:///*"
  ],
  "permissions": [
    "activeTab",
    "storage",
    "scripting",
    "downloads"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "48": "icon48.png",
    "64": "icon64.png",
    "96": "icon.png",
    "128": "icon128.png"
  }
}