A searchable guide to the complete WordPress Icon Library (@wordpress/icons) package from Gutenberg.
import { Icon, headingLevel4 } from '@wordpress/icons';
<Icon icon={headingLevel4} />
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true" focusable="false"><path d="M20 13V7h-3l-4 6v2h5v2h2v-2h1v-2h-1zm-2 0h-2.8L18 9v4zm-9-2H5V7H3v10h2v-4h4v4h2V7H9v4z"></path></svg>
headingLevel4 – WordPress Icon Library