const Link: React.FC<{ url: string, children: React.ReactNode }> = ({ url, children }) => <a href={url}>{children}</a>

type Props = {
    children?: React.ReactElement<typeof Link>
}

const Component: React.FC<Props> = ({children}) => <div>{children}</div>;

// ok
<Component><Link url="">asdf</Link></Component>;

// @ts-expect-error
<Component>asdf</Component>;

// @ts-expect-error 
<Component>
    <Link url="">asdf</Link>
    <Link url="">asdf</Link>
</Component>;

// @ts-expect-error - This should be an error!
<Component>
    <span>asfd</span>
</Component>;