Examine source code of Important delivery icons

{
  "manifest_version": 2,
  "name": "Important delivery icons",
  "version": "1.0",
  "description": "The important delivery symbol is often used to emphasize that a package is especially important, requires priority handling, or requires special attention during shipping or delivery.",
  "icons": {
    "48": "icon.png"
  },
  "browser_action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Click me!"
  },
  "permissions": [
    "activeTab"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{12e2f525-4fb3-40f0-b7d7-c63089167197}"
    }
  }
}