Examine source code of Invidious Redirection

{
  "manifest_version": 2,
  "name": "Invidious Instance Selector",
  "version": "1.1",
  "description": "Allows users to select an Invidious instance.",
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "https://docs.invidious.io/*"
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "255": "images/icon.png"
    }
  },
  "icons": {
    "255": "images/icon.png"
  },
  "licenses": [
    {
      "name": "GNU General Public License (GPL) Version 3",
      "url": "https://www.gnu.org/licenses/gpl-3.0.html"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{41a851ed-5ea8-4135-a9c3-9d9f6e3137cb}"
    }
  }
}