ant-design/components/back-top/demo/basic.tsx

import React from 'react';
import { BackTop } from 'antd';

const App: React.FC = () => (
  <>
    <BackTop />
    Scroll down to see the bottom-right
    <strong className="site-back-top-basic"> gray </strong>
    button.
  </>
);

export default App;