Examine source code of urlscan.io

{
  "manifest_version": 3,
  "name": "urlscan.io",
  "description": "A sandbox for the web",
  "version": "0.2.0",
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png",
    "128": "icon-128.png"
  },
  "host_permissions": [
    "https://urlscan.io/*"
  ],
  "permissions": [
    "storage",
    "notifications",
    "tabs",
    "contextMenus"
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self';",
    "sandbox": "sandbox allow-scripts allow-forms allow-popups allow-modals; script-src 'self' 'unsafe-inline' 'unsafe-eval'; child-src 'self';"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{6d595354-bc7c-4abb-a206-9dab026717cd}"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_title": "urlscan.io",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "open_in_tab": true,
    "page": "options.html"
  }
}