Examine source code of Map Elements

{
  "name": "Map Elements",
  "description": "Mapping website elements",
  "version": "1.0",
  "manifest_version": 3,
  "options_ui": {
    "page": "options.html"
  },
  "permissions": [
    "activeTab",
    "scripting"
  ],
  "action": {
    "default_title": "Map Elements",
    "default_popup": "index.html"
  },
  "icons": {
    "16": "images/map-elements-16.png",
    "32": "images/map-elements-32.png",
    "48": "images/map-elements-48.png",
    "128": "images/map-elements-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "map-elements@example.com"
    }
  }
}