Integrate Razorpay Payment Gateway in PhP CodeIgniter

<?php
defined('BASEPATH') OR exit('No direct script access allowed');
require_once(APPPATH."libraries/razorpay/razorpay-php/Razorpay.php");


use Razorpay\Api\Api;
use Razorpay\Api\Errors\SignatureVerificationError;

class Register extends CI_Controller {
    /**
     * This function loads the registration form
     */
    public function index()
    {$this->load->helper('url');
        $this->load->view('registration-form');
    }

    /**
     * This function creates order and loads the payment methods
     */
    public function pay()
    {
        $api = new Api(RAZOR_KEY, RAZOR_SECRET_KEY);
        /**
         * You can calculate payment amount as per your logic
         * Always set the amount from backend for security reasons
         */
        $_SESSION['payable_amount'] = 10;
        $razorpayOrder = $api->order->create(array(
            'receipt'         => rand(),
            'amount'          => $_SESSION['payable_amount'] * 100, /* rupees in paise */ 
            'currency'        => 'INR',
            'payment_capture' => 1 // auto capture 

        ));

        $amount = $razorpayOrder['amount'];
        $razorpayOrderId = $razorpayOrder['id'];
        $_SESSION['razorpay_order_id'] = $razorpayOrderId;
        $data = $this->prepareData($amount,$razorpayOrderId);
        $this->load->view('rezorpay',array('data' => $data));
    }

    /**
     * This function verifies the payment,after successful payment
     */
    public function verify()
    {
        $success = true;
        $error = "payment_failed";
        if (empty($_POST['razorpay_payment_id']) === false) {
            $api = new Api(RAZOR_KEY, RAZOR_SECRET_KEY);
        try {
                $attributes = array(
                    'razorpay_order_id' => $_SESSION['razorpay_order_id'],
                    'razorpay_payment_id' => $_POST['razorpay_payment_id'],
                    'razorpay_signature' => $_POST['razorpay_signature']                );
                $api->utility->verifyPaymentSignature($attributes);
            } catch(SignatureVerificationError $e) {
                $success = false;
                $error = 'Razorpay_Error : ' . $e->getMessage();
            }
        }
        if ($success == true) {
            echo "<pre>";
            print_r($attributes) ;
            /**
             * Call this function from where ever you want
             * to save save data before of after the payment
             */
            //$this->setRegistrationData();

            //redirect(base_url().'register/success');
        }
        else {
            //redirect(base_url().'register/paymentFailed');
        }
    }

    /**
     * This function preprares payment parameters
     * @param $amount
     * @param $razorpayOrderId
     * @return array
     */
 
public function prepareData($amount,$razorpayOrderId )
    {  
        $data = array(
            "key" => RAZOR_KEY,
            "amount" => $amount,
            "name" => "Coding Birds Online",
            "description" => "Learn To Code",
            "image" => "https://demo.codingbirdsonline.com/website/img/coding-birds-online/coding-birds-online-favicon.png",
            "prefill" => array(
                "name"  => $this->input->post('name'),
                "email"  => $this->input->post('email'),
                "contact" => $this->input->post('contact'),
            ),
            "notes"  => array(
                "address"  => "Hello World",
                "merchant_order_id" => rand(),
            ),
            "theme"  => array(
                "color"  => "#F37254"
            ),
            "order_id" => $razorpayOrderId,
        );
        return $data;
    }

    /**
     * This function saves your form data to session,
     * After successfull payment you can save it to database
     */
    public function setRegistrationData()
    {
        $name = $this->input->post('name');
        $email = $this->input->post('email');
        $contact = $this->input->post('contact');
        $amount = $_SESSION['payable_amount'];

        $registrationData = array(
            'order_id' => $_SESSION['razorpay_order_id'],
            'name' => $name,
            'email' => $email,
            'contact' => $contact,
            'amount' => $amount,
        );
        // save this to database


    }

    /**
     * This is a function called when payment successful,
     * and shows the success message
     */
    public function success()
    {
        $this->load->view('success');
    }
    /**
     * This is a function called when payment failed,
     * and shows the error message
     */
    public function paymentFailed()
    {
        $this->load->view('error');
    }   
}