Discount badge does not display on product page

I tried the following code to add a discount badge ( -xx% ) in a circle on my product images:

function filter_woocommerce_single_product_image_thumbnail_html( $html, $post_thumbnail_id ) {
    // Get the global product object
    global $product;
    
    // Is a WC product
    if ( is_a( $product, 'WC_Product' ) ) {
        
        // On sale
        $is_on_sale = $product->is_on_sale();
        
        // True
        if ( $is_on_sale ) {
            $rrp_price        = (int) $product->get_regular_price();
            $sale_price       = (int) $product->get_price();
            
            // Greater than
            if ( $rrp_price > $sale_price ) {
                $discount_amount  = $rrp_price - $sale_price;
                $discount_percent = '-' . round( ( $discount_amount / $rrp_price ) * 100, 0 ) . '%';
                $html             = '<span class="wpd-sale-thumbnail"><span class="wpd-sale-badge">' . $discount_percent . '</span>' . $html . '</span>';
            }
        }
    }
 
    return $html;
}
add_filter( 'woocommerce_single_product_image_thumbnail_html', 'filter_woocommerce_single_product_image_thumbnail_html', 10, 2 );

However it does not show? Can i get some guidance as to why that is ?

• This topic was modified 3 years, 4 months ago by thefrisb.

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