You can refer to the following steps to support IE11:
First, install the package: npm install react-app-polyfill
.
Second, add import 'react-app-polyfill/ie11'; import 'react-app-polyfill/stable';
at the first line in src/index.js.
Third, add ie 11
in package.json like this:
Finally, you can restart your app and it will work in IE11. If it still doesn’t work, delete the app and create it again according to the above steps.