Change ‘Add to cart’ text to custom text on a button, WooCommerce

add_filter( 'woocommerce_product_add_to_cart_text' , 'custom_woocommerce_product_add_to_cart_text' );


function custom_woocommerce_product_add_to_cart_text() 
    {
        global $product;
        $product_type = $product->product_type;
        switch ( $product_type )

        {
            case 'external':
            return __( 'More', 'woocommerce' );
            break;
            case 'grouped':
            return __( 'More', 'woocommerce' );
            break;
            case 'simple':
            return __( 'More', 'woocommerce' );
            break;
            case 'variable':
            return __( 'More', 'woocommerce' );
            break;
            default:
            return __( 'More', 'woocommerce' ); 
        }
}