Examine source code of Response Time Clock

{
  "manifest_version": 3,
  "name": "Response Time Clock",
  "version": "0.1.4",
  "description": "Shows approximate site time from HTTP Date response headers, with local timezone conversion and uncertainty.",
  "permissions": [
    "webRequest",
    "activeTab",
    "storage"
  ],
  "optional_host_permissions": [
    "http://*/*",
    "https://*/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_title": "Response Time Clock",
    "default_popup": "popup.html",
    "default_icon": "icons/icon.svg"
  },
  "icons": {
    "48": "icons/icon.svg",
    "96": "icons/icon.svg"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "response-time-clock@example.local",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}