Examine source code of YouTube Blocker

{
  "manifest_version": 2,
  "name": "YouTube Blocker",
  "version": "1.1",
  "browser_specific_settings": {
    "gecko": {
      "id": "youtube-blocker@local",
      "strict_min_version": "112.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "description": "Blocks access to YouTube for productivity",
  "permissions": [
    "webRequest",
    "webRequestBlocking",
    "storage",
    "*://*.youtube.com/*",
    "*://*.youtu.be/*",
    "*://*.youtube-nocookie.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/icon-48.svg"
    }
  },
  "icons": {
    "48": "icons/icon-48.svg",
    "96": "icons/icon-96.svg"
  }
}