Fetch API cannot load https://cdn.flexmonster.com/2.4/toolbar/flexmonster.toolbar.js. No ‘Access-Control-Allow-Origin’ header is present on the requested resource. Origin ‘http://localhost:3000’ is therefore not allowed access. If an opaque response serves your needs, set the request’s mode to ‘no-cors’ to fetch the resource with CORS disabled.
You can always use the toolbar from the download package to avoid any cross-origin issues.