Как добавить поле / Quebec Snowflake?
Используйте фильтры:


add_filter('tcm_metabox_tyres', function ($metabox) 
{
	$metabox['fields'][] = [
					'id'	=> 'quebec_snowflake',
					'name'	=> __( 'Quebec Snowflake', 'tac-pneu' ),
					'type'	=> 'select',
					'options' => [
						'no'	=> __( 'no', 'tac-pneu' ),
						'yes'	=> __( 'yes', 'tac-pneu' ),
					],
					'class'	=> 'tcm-quebec_snowflake',
				];

	return $metabox;
});


add_action('tcm_product_meta_end', function ($metabox) 
{
	if ( $meta = rwmb_meta( 'quebec_snowflake' ) )	
	{
		echo '' . __( 'Quebec SnowFlake', 'tac-pneu' ) . " ";
		echo "";
		echo '';
	}
});

add_action( 'woocommerce_after_shop_loop_item', function()
{
	if ( $meta = rwmb_meta( 'quebec_snowflake' ) )	
	{
		echo '';
	}


}, 10 );