Examine source code of Prext

{
  "name": "PREXT",
  "description": "Redirects YouTube, Reddit, Twitter, and Wikipedia to privacy respecting frontends.",
  "version": "1.0",
  "manifest_version": 2,
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "512": "cam.png"
  },
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "*://*.reddit.com/*",
    "*://*.youtube.com/*",
    "*://*.twitter.com/*",
    "*://*.wikipedia.org/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{fbf67809-1712-4e48-825f-ce71b3aae70c}"
    }
  }
}