WooCommerce Custom Text Area Field For Editing Products

/**
 * Snippet Name:     WooCommerce Custom Product Text Area Metabox
 * Snippet Author:   ecommercehints.com
*/

// Create the custom product metabox
add_action ('woocommerce_product_options_advanced', 'ecommercehints_custom_product_textarea_metabox');
function ecommercehints_custom_product_textarea_metabox() {
   echo '<div class="options_group">';
   woocommerce_wp_textarea_input (array ( // A textarea type field
      'id'                => 'custom_product_textarea_metabox',
      'value'             => get_post_meta (get_the_ID(), 'custom_product_textarea_metabox', true),
      'label'             => 'This is the label',
      'description'       => 'This is the description',
      'desc_tip'          => true // If true, place description in question mark tooltip.
  ));
   echo '</div>';
}

// Save data entered in the product metabox
add_action ('woocommerce_process_product_meta', 'ecommercehints_save_field_on_update', 10, 2);
function ecommercehints_save_field_on_update ($id, $post) {
      update_post_meta ($id, 'custom_product_textarea_metabox', $_POST['custom_product_textarea_metabox']);
}

global $product;
$custom_product_textarea_metabox = $product->get_meta ('custom_product_textarea_metabox');
echo $custom_product_textarea_metabox;