Examine source code of 12Startpage.com

{
  "name": "12StartPage.com - Personal Startpage Manager",
  "description": "Start the web with 12StartPage.com",
  "manifest_version": 2,
  "version": "2.3resigned1",
  "homepage_url": "https://www.12startpage.com",
  "icons": {
    "16": "icon16.png",
    "32": "icon32.png",
    "48": "icon48.png"
  },
  "applications": {
    "gecko": {
      "strict_min_version": "54.0",
      "id": "{0a79bc58-665f-4534-a7ea-6d61d68194fb}"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "16": "icon16.png"
    },
    "default_title": "12StartPage.com",
    "default_popup": "popup.html"
  },
  "chrome_url_overrides": {
    "newtab": "redirect.html"
  },
  "permissions": [
    "*://12startpage.com/*",
    "tabs",
    "activeTab",
    "management",
    "cookies",
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.12startpage.com/*"
      ],
      "js": [
        "content.js"
      ],
      "all_frames": false,
      "run_at": "document_end"
    }
  ]
}