Examine source code of Calculator A2Z

{
  "manifest_version": 3,
  "name": "Calculator A2Z",
  "description": "Quick access to all your favorite calculators from CalculatorA2Z.com",
  "version": "1.0",
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/calculatora2zicon.png",
      "48": "icons/calculatora2zicon.png",
      "128": "icons/calculatora2zicon.png"
    }
  },
  "icons": {
    "16": "icons/calculatora2zicon.png",
    "48": "icons/calculatora2zicon.png",
    "128": "icons/calculatora2zicon.png"
  },
  "permissions": [
    "storage"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "prince.jindal8@gmail.com",
      "strict_min_version": "109.0"
    }
  }
}