Custom post meta for product name

Hi Dario,

Instead of using post title as product name, I prefer to use a custom post meta value. I’m using this code on yasr-functions.php but it didn’t work. Could you please advise? Thanks in advance.

$check_product_rating = get_post_meta( $post_id, 'product_rating', true );
  if ( !empty($check_product_rating))  {
	$rich_snippet["name"] = $check_product_rating;
	$rich_snippet["brand"] = $check_product_rating;
	$rich_snippet["description"] = $review_name;
        }
	else
	{
	$rich_snippet["name"] = $review_name;
	}