Examine source code of MyNewTabStyle

{
  "name": "NewTab",
  "version": "1.3.0",
  "manifest_version": 2,
  "icons": {
    "48": "Assest/img/48.png",
    "96": "Assest/img/96.png"
  },
  "chrome_url_overrides": {
    "newtab": "Index.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{195f5b1f-93fb-40ea-b1be-19169bc81957}"
    }
  }
}