Examine source code of NO+OTP

{
  "manifest_version": 2,
  "name": "NO+OTP",
  "description": "Add to the input your password + OTP",
  "version": "3.0",
  "options_ui": {
    "page": "options.html",
    "browser_style": true,
    "open_in_tab": true
  },
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "60.0",
      "id": "{331d643d-ad4b-414f-b884-90c1cf38ccab}"
    }
  },
  "icons": {
    "48": "images/unlock-50.png",
    "128": "images/unlock-128.png"
  },
  "browser_action": {
    "default_title": "NO+OTP"
  },
  "background": {
    "page": "index.html"
  },
  "permissions": [
    "storage",
    "activeTab",
    "clipboardWrite"
  ]
}