Examine source code of Duck New Tab Home Page

{
  "name": "Duck New Tab",
  "description": "Duck New Tab Home Page",
  "version": "1.0",
  "browser_specific_settings": {
    "gecko": {
      "id": "{6e76e267-d527-137e-1bd7-9a6587616437}"
    }
  },
  "manifest_version": 3,
  "offline_enabled": true,
  "icons": {
    "128": "icons/icon128.png"
  },
  "chrome_url_overrides": {
    "newtab": "index.html"
  },
  "chrome_settings_overrides": {
    "homepage": "index.html"
  },
  "action": {
    "default_title": "New Tab"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  }
}