Examine source code of Finance Autofill Pro

{
  "manifest_version": 2,
  "name": "Finance Autofill Pro",
  "version": "2.1",
  "description": "Professional financial form autofill for Firefox",
  "author": "Your Name",
  "applications": {
    "gecko": {
      "id": "finance-autofill@yourdomain.com",
      "strict_min_version": "78.0"
    }
  },
  "browser_action": {
    "default_icon": "icons/icon-48.png",
    "default_popup": "popup/popup.html",
    "default_title": "Financial Autofill"
  },
  "permissions": [
    "storage",
    "*://*.quickbooks.com/*",
    "*://*.netsuite.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.quickbooks.com/*",
        "*://*.netsuite.com/*"
      ],
      "js": [
        "content_scripts/autofill.js"
      ]
    }
  ]
}