Examine source code of Markbook

{
  "name": "Markbook",
  "description": "No more hustle with bookmarks. Get free search and mark tab feature.",
  "version": "0.1",
  "manifest_version": 3,
  "permissions": [
    "tabs",
    "activeTab",
    "scripting"
  ],
  "action": {
    "default_popup": "popup.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "ujjwal.raj.5798@gmail.com"
    }
  }
}