Examine source code of Jelly Party

{
  "name": "Jelly Party",
  "version": "2.3.0",
  "description": "Watch videos with your friends — in sync!",
  "manifest_version": 3,
  "permissions": [
    "activeTab",
    "tabs",
    "storage",
    "scripting"
  ],
  "host_permissions": [
    "https://join.jelly-party.com/*",
    "https://meet.jelly-party.com/*"
  ],
  "optional_host_permissions": [
    "https://*/*",
    "http://*/*"
  ],
  "action": {
    "default_icon": {
      "16": "16x16.png",
      "32": "32x32.png",
      "48": "48x48.png",
      "128": "128x128.png"
    }
  },
  "background": {
    "scripts": [
      "src/background/index.js"
    ],
    "type": "module"
  },
  "content_scripts": [
    {
      "matches": [
        "https://join.jelly-party.com/join*"
      ],
      "js": [
        "src/content/join.js"
      ],
      "run_at": "document_start"
    }
  ],
  "icons": {
    "16": "16x16.png",
    "32": "32x32.png",
    "48": "48x48.png",
    "128": "128x128.png"
  },
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'; connect-src 'self' wss://meet.jelly-party.com https://meet.jelly-party.com"
  },
  "sidebar_action": {
    "default_panel": "src/sidebar/sidebar.html",
    "open_at_install": false
  },
  "commands": {
    "_execute_sidebar_action": {
      "suggested_key": {
        "default": "Alt+Shift+J"
      }
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1bce6a35-61f2-4477-9899-842359eadcef}",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "browsingActivity",
          "personalCommunications",
          "personallyIdentifyingInfo",
          "websiteActivity"
        ]
      }
    }
  }
}