Examine source code of TabPurger

{
  "manifest_version": 3,
  "name": "TabPurger",
  "version": "1.2.0",
  "description": "Detects and closes duplicate browser tabs. Manual or automatic. Powered by TabPurger — https://tabpurger.aktulun.dev",
  "homepage_url": "https://tabpurger.aktulun.dev",
  "icons": {
    "16": "icons/icon-16.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "action": {
    "default_icon": {
      "16": "icons/icon-16.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    },
    "default_title": "TabPurger",
    "default_popup": "popup.html"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "permissions": [
    "tabs",
    "notifications",
    "storage",
    "alarms"
  ],
  "host_permissions": [],
  "browser_specific_settings": {
    "gecko": {
      "id": "tabpurger@aktulun.dev",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  }
}