CODE EXAMPLE FOR PHP

wc get product category image

    <?php
        if ( is_product_category() ){

            global $wp_query;
            $cat = $wp_query->get_queried_object();    
            $thumbnail_id = get_woocommerce_term_meta( $cat->term_id, 'thumbnail_id', true ); 
            $image = wp_get_attachment_url( $thumbnail_id ); 
            echo "<img src='{$image}' alt='' />";
        }
    ?>