Examine source code of Business Calculator

{
  "manifest_version": 3,
  "name": "Business Calculator",
  "version": "1.0.0",
  "description": "Premium all-in-one business calculators — profit, margin, tax, VAT, EMI, ROI, GST and more. Fast, offline, elegant.",
  "author": "Mr Tarek",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_title": "Business Calculator",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png"
    }
  },
  "permissions": [
    "storage"
  ],
  "host_permissions": [
    "https://api.frankfurter.app/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "business-calculator@mrtarek",
      "strict_min_version": "115.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'"
  }
}