Adding custom post type to

Hi deodev!

One way I can think of would be using the pre_get_posts filter.

Something like:

add_filter( 'pre_get_posts', 'add_post_types_to_author' );
function add_post_types_to_author( $query ){
	// set the new post type to return, and check if we are in
	// an author archive page
	if( $query->is_main_query() && !is_admin() && $query->is_author() ){
		$query->set( 'post_type', array( 'post', 'page', 'download' ) );
    }

	// Return our new query
	return $query;
}

Sort of a rough start but you can alter to your choosing. You can use that in a child theme’s funtcions.php file, or a parent theme’s functions.php file, or even a functionality plugin. A little more information about the filter:
https://codex.wordpress.org/Plugin_API/Action_Reference/pre_get_posts

Hope that helps!