This code has worked well to introduce the second stylesheet style_test.css
/* add link to stylesheet to the head section */
add_action( 'wp_enqueue_scripts', function() {
$child_folder = trailingslashit( get_stylesheet_directory_uri() );
wp_enqueue_style( 'style', $child_folder . 'style_test.css' );
} );
If I may I will start another topic as I am not sure how to make this only load for one page
thank you, Paul