Add gallery thumbs to woocommerce shop page

functions.php

//* Add gallery thumbs to woocommerce shop page
add_action('woocommerce_shop_loop_item_title','wps_add_extra_product_thumbs', 5);
function wps_add_extra_product_thumbs() {

	if ( is_shop() ) {

		global $product;

		$attachment_ids = $product->get_gallery_attachment_ids();

		echo '<div class="product-thumbs">';

		foreach( array_slice( $attachment_ids, 0,3 ) as $attachment_id ) {

		  	$thumbnail_url = wp_get_attachment_image_src( $attachment_id, 'thumbnail' )[0];

		  	echo '<img class="thumb" src="' . $thumbnail_url . '">';

		}

		echo '</div>';
	
	}

 }