Examine source code of Weather Widget

{
  "manifest_version": 3,
  "name": "Weather Widget",
  "version": "1.0.0",
  "description": "Display current weather information",
  "browser_specific_settings": {
    "gecko": {
      "id": "weather-widget@example.com"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_title": "Weather Widget"
  }
}