WordPress Post author link filter for adding Schema.org itemprop attribute

functions.php

function schema_org_author_posts_link( $link ) {
	$link = sprintf( '<a itemprop="author" itemscope itemtype="https://schema.org/Person" href="%1$s" title="%2$s" rel="author"><span itemprop="name">%3$s</span></a>',
		esc_url( get_author_posts_url( $authordata->ID, $authordata->user_nicename ) ),
		/* translators: %s: author's display name */
		esc_attr( sprintf( __( 'Posts by %s' ), get_the_author() ) ),
		get_the_author()
	);

	return $link;
}
add_filter( 'the_author_posts_link', 'schema_org_author_posts_link' );