Examine source code of Tab Manager Pro

{
  "manifest_version": 3,
  "name": "Tab Manager Pro",
  "version": "1.3",
  "description": "Helps the user manage their tabs in a constructive way, leading a popup at a definable number of tabs opened. Certain actions are able to be done when you decide to do something about it, such as separating into a new window, or simply closing them.",
  "icons": {
    "48": "favicon.ico"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{2f4a50fc-345a-49be-990b-4cb8d0c7cc76}"
    }
  },
  "host_permissions": [
    "<all_urls>",
    "https://cdn.jsdelivr.net/"
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self' object-src 'self'"
  },
  "background": {
    "scripts": [
      "background-script.js"
    ]
  },
  "permissions": [
    "tabs",
    "storage"
  ],
  "action": {
    "default_popup": "Tabs/settings.html"
  }
}