Examine source code of NERD IP info

{
  "manifest_version": 3,
  "browser_specific_settings": {
    "gecko": {
      "id": "nerd@cesnet.cz",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "browsingActivity"
        ],
        "has_previous_consent": false
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "name": "NERD IP info",
  "description": "Detects IPv4 addresses on web pages, queries the CESNET NERD API, and displays results in an interactive popup.",
  "version": "1.0.4",
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "storage",
    "contextMenus",
    "activeTab",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content/contentScript.js"
      ],
      "css": [
        "content/contentStyle.css"
      ],
      "run_at": "document_end"
    }
  ],
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "48": "icons/icon-48.png"
    }
  },
  "options_page": "options/options.html",
  "web_accessible_resources": [
    {
      "resources": [
        "icons/icon-16.png",
        "icons/icon-32.png",
        "icons/icon-48.png",
        "icons/icon-128.png",
        "icons/icon-gray.png",
        "icons/icon-green.png",
        "icons/icon-orange.png",
        "icons/icon-red.png",
        "icons/icon-purple.png"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'"
  }
}