Examine source code of 3x youtube

{
  "manifest_version": 3,
  "name": "3x youtube",
  "version": "1.8.0",
  "description": "Extends YouTube's native playback speed control up to 5x.",
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://www.youtube.com/*",
        "https://m.youtube.com/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "youtube-5x-speed@local.extension",
      "strict_min_version": "115.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {}
  }
}