Examine source code of Session Managor

{
  "manifest_version": 3,
  "name": "Session Manager",
  "version": "1.0",
  "description": "Save and restore tab sessions.",
  "action": {
    "default_popup": "popup.html",
    "default_icon": "session_manager.png"
  },
  "icons": {
    "128": "session_manager.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "gouldh7071999fqetz@hotmail.com"
    }
  }
}