Examine source code of Bookmark Tabs

{
  "manifest_version": 3,
  "name": "Bookmark Tabs",
  "version": "2.0.3",
  "description": "Saves selected or all tabs into a timestamped bookmark folder",
  "author": "4dash2 <aloktripathi.517@gmail.com>",
  "developer": {
    "name": "4dash2",
    "url": "mailto:aloktripathi.517@gmail.com"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "bookmark-tabs@4dash2",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "16": "icon-16.png",
    "32": "icon-32.png",
    "48": "icon-48.png",
    "96": "icon-96.png",
    "128": "icon-128.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_area": "navbar",
    "default_popup": "popup.html",
    "default_icon": "icon.png"
  },
  "permissions": [
    "menus",
    "tabs",
    "bookmarks",
    "storage"
  ],
  "optional_permissions": [
    "notifications"
  ],
  "commands": {
    "_execute_action": {},
    "bookmark-tabs": {}
  }
}