Show an iframe on specific product thumbnail

i want to show an iframe on specific product thumbnail image.

https://prntscr.com/j5jhz8

i use this code but its not working. Please correct me if i am doing something wrong.

function feature_image_to_3d() {
 
// Do this for product ID = 31 only
if ( is_single ( '31' ) ) {
echo '<div class="woocommerce-product-gallery">';

// get video embed HTML from YouTube
echo '<div class="sketchfab-embed-wrapper">
<iframe style="width="50%" height="480" src="https://www.ads-software.com/" ></iframe>

</div>';

echo '</div>';
}
 
}

add_action( 'woocommerce_product_thumbnails', 'feature_image_to_3d', 100 );

many thanks

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