How to import Ant Design css styles in GlobalStyles of styled-components.?

You shouldn't.

NOTE: At this time we recommend not using @import inside of createGlobalStyle. We're working on better behavior for this functionality but it just doesn't really work at the moment and it's better if you just embed these imports in your HTML index file, etc.

Altought you can try:

import { createGlobalStyle, css } from 'styled-components';

const antdCss = css`
  ${import('antd/dist/antd.css')}
`;

const GlobalStyle = createGlobalStyle`
  ${antdCss}
`;

export default GlobalStyle;