Examine source code of Auto-Close-Tabs-for-Zen

{
  "manifest_version": 3,
  "name": "Auto Close Tabs",
  "version": "1.1.3",
  "description": "Automatically close inactive tabs after a configurable period of inactivity",
  "browser_specific_settings": {
    "gecko": {
      "id": "auto-close-tabs@zen-extension",
      "strict_min_version": "128.0"
    }
  },
  "permissions": [
    "tabs",
    "alarms",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_icon": {
      "48": "icons/icon-48.svg",
      "96": "icons/icon-96.svg"
    }
  },
  "options_ui": {
    "page": "popup/popup.html",
    "open_in_tab": false
  },
  "icons": {
    "48": "icons/icon-48.svg",
    "96": "icons/icon-96.svg"
  }
}