How do you entry woocommerce google feed fields? [closed]

I’ve the WooCommerce Google Feed extension put in. Each product has customized Google Feed Fields. I’m attempting to get the GTIN subject. However it simply return clean knowledge. The docs do not present any examples. Questioning if anybody else has figured this out?

perform lw_woocommerce_gpf_title( $title, $product_id ) {
    $product = wc_get_product( $product_id );
    $gtin = $product->get_meta( 'gtin' );
        $title = $title." - ".$gtin;

    
    return $title;
}
add_filter( 'woocommerce_gpf_title', 'lw_woocommerce_gpf_title', 10, 2 );