Add to cart button on shop / archive page for group buy

/* Add to cart button on shop / archive page for group buy */

function custom_woocommerce_loop_add_to_cart_args( $args, $product ){
    if ( $product->get_type() == 'groupbuy' ) {
        $args['class'] = $args['class'] . ' ajax_add_to_cart';
    }
    return $args;
}

add_filter( 'woocommerce_loop_add_to_cart_args', 'custom_woocommerce_loop_add_to_cart_args', 10, 2 );