/*******A SIDE BY SIDE CHECKOUT PAGE, Places text: Order Details & Payment Processing on checkout page-Copy and Paste contents of this file into a (PHP FILE) snippet*******/
add_action('woocommerce_review_order_before_order_total', 'n2t_woocommerce_review_order_before_order_total', 1);
function n2t_woocommerce_review_order_before_order_total() {
    if ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
        return; // Exit if it's an AJAX request
    }
    echo '<div style="text-align: center;"> <h3> Order Details & Payment Processing </h3> </div>'; // Replace with your custom text
}