Examine source code of Simple IP Checker

{
  "manifest_version": 2,
  "name": "IP Checker",
  "version": "1.1",
  "description": "This extension allows users to easily check their internet IP address directly from their browser. With just a click, users can quickly retrieve this information, making it a convenient tool for anyone who needs to know their internet IP address for various purposes. Whether it's for troubleshooting network issues, configuring network settings, or simply satisfying curiosity, your extension provides a quick and easy way to access this important information.",
  "icons": {
    "48": "icon.png"
  },
  "permissions": [
    "activeTab",
    "webRequest",
    "webRequestBlocking",
    "<all_urls>"
  ],
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{da3900f0-b649-42b2-a3d6-7f601d1964ac}"
    }
  }
}