Examine source code of BlueArchive Tab

{
  "manifest_version": 2,
  "name": "Customizable New Tab",
  "version": "1.0",
  "description": "Customizes your new tab",
  "chrome_url_overrides": {
    "newtab": "tab.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{26088eb4-0b75-420e-ad1e-8daf3c528c1b}"
    }
  }
}