Examine source code of Sync Watch

{
  "manifest_version": 2,
  "name": "Sync Watch",
  "version": "1.0.4",
  "description": "Synchronized video watching with friends",
  "browser_specific_settings": {
    "gecko": {
      "id": "sync-watch@legacyundefined.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "storage",
    "activeTab",
    "tabs",
    "alarms",
    "https://*.netflix.com/*",
    "https://*.youtube.com/*",
    "https://*.disneyplus.com/*",
    "https://*.hulu.com/*",
    "https://*.hbomax.com/*",
    "https://*.max.com/*",
    "https://*.primevideo.com/*",
    "https://*.amazon.com/*",
    "https://*.media-amazon.com/*",
    "https://*.cloudfront.net/*",
    "https://*.paramountplus.com/*",
    "https://*.aiv-cdn.net/*",
    "https://*.aiv-delivery.net/*",
    "https://*.pv-cdn.net/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.netflix.com/*",
        "https://*.youtube.com/*",
        "https://*.disneyplus.com/*",
        "https://*.hulu.com/*",
        "https://*.hbomax.com/*",
        "https://*.max.com/*",
        "https://*.primevideo.com/*",
        "https://*.amazon.com/*",
        "https://*.media-amazon.com/*",
        "https://*.cloudfront.net/*",
        "https://*.paramountplus.com/*",
        "https://*.aiv-cdn.net/*",
        "https://*.aiv-delivery.net/*",
        "https://*.pv-cdn.net/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  }
}