Modify the information to display in the Author's archive page.

author-archive-cpt.php

<?php
//* Do NOT include the opening php tag

// filter the content to display on the Author's archive page
function nice_cpt_author_archive( $query ) {

	if ( $query->is_author ) {
		$arr_post_types = array( 'post', 'article' ); // Edit this array as you need.
		$query->set( 'post_type', $arr_post_types );
	}
}
add_action( 'pre_get_posts', 'nice_cpt_author_archive' );