Can't update database after PayPal transaction in CodeIgniter 4

I integrating PayPal in Codeigniter 4 but I can't get data after the transaction for an updated database

What I want to do is to get a PayPal response from the IPN listener so that I can modify my database accordingly, but no matter what I do, it just won't work. I have already done the following in my PayPal Sandbox account:

1. Enabled Auto Return
2. Set Auto Return URL ('dashboard')
3. Enabled Payment Data Transfer (PDT)
4. Enabled IPN message reception
5. Set IPN URL ('http:myDomain/Controller/index')The redirect to Auto Return URL not working fine too, after the transaction, the user can't back to the store until clicking the return button.

I can't get data in the database, I am sending data

        function index(){    $raw_post_data = file_get_contents('php://input');    $raw_post_array = explode('&', $raw_post_data);    $myPost = array();    foreach ($raw_post_array as $keyval) {        $keyval = explode('=', $keyval);        if (count($keyval) == 2)            $myPost[$keyval[0]] = urldecode($keyval[1]);    }    $req = 'cmd=_notify-validate';    if (function_exists('get_magic_quotes_gpc')) {        $get_magic_quotes_exists = true;    }    foreach ($myPost as $key => $value) {        if ($get_magic_quotes_exists == true && get_magic_quotes_gpc() == 1) {            $value = urlencode(stripslashes($value));        } else {            $value = urlencode($value);        }        $req .= "&$key=$value";    }    if (sandbox == true) {        $paypal_url = "https://www.sandbox.paypal.com/cgi-bin/webscr";    } else {        $paypal_url = "https://www.paypal.com/cgi-bin/webscr";    }    $ch = curl_init($paypal_url);    if ($ch == FALSE) {        return FALSE;    }    curl_setopt($ch, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);    curl_setopt($ch, CURLOPT_POST, 1);    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);    curl_setopt($ch, CURLOPT_POSTFIELDS, $req);    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 1);    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);    curl_setopt($ch, CURLOPT_FORBID_REUSE, 1);    if (DEBUG == true) {        curl_setopt($ch, CURLOPT_HEADER, 1);        curl_setopt($ch, CURLINFO_HEADER_OUT, 1);    }    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 30);    curl_setopt($ch, CURLOPT_HTTPHEADER, array('Connection: Close'));    $res = curl_exec($ch);    if (curl_errno($ch) != 0) // cURL error    {        if (DEBUG == true) {            error_log(date('[Y-m-d H:i e] ') . "Can't connect to PayPal to validate IPN message: " . curl_error($ch) . PHP_EOL, 3, LOG_FILE);        }        curl_close($ch);        exit;    } else {        // Log the entire HTTP response if debug is switched on.        if (DEBUG == true) {            error_log(date('[Y-m-d H:i e] ') . "HTTP request of validation request:" . curl_getinfo($ch, CURLINFO_HEADER_OUT) . " for IPN payload: $req" . PHP_EOL, 3, LOG_FILE);            error_log(date('[Y-m-d H:i e] ') . "HTTP response of validation request: $res" . PHP_EOL, 3, LOG_FILE);        }        curl_close($ch);    }    // Inspect IPN validation result and act accordingly    // Split response headers and payload, a better way for strcmp    $tokens = explode("\r\n\r\n", trim($res));    $res = trim(end($tokens));    if (strcmp($res, "VERIFIED") == 0) {        // assign posted variables to local variables        $paypalInfo    = $this->input->post();        $aData = array();        $item_name = $_POST['item_name'];        $data['product_id']    = $paypalInfo["item_number"];        $data['txn_id']    = $paypalInfo["txn_id"];        $data['payment_gross'] = $paypalInfo["mc_gross"];        $data['currency_code'] = $paypalInfo["mc_currency"];        $data['payer_email'] = $paypalInfo["payer_email"];        $data['payment_status']    = $paypalInfo["payment_status"];        // check whether the payment_status is Completed        $isPaymentCompleted = false;        if ($paypalInfo["payment_status"] == "Completed") {            $isPaymentCompleted = true;        }        if ($isPaymentCompleted) {            $oPaypalBuilder = $this->modelHelper->getBuilder('Paypal');            $oPaypalBuilder->skipValidation();            $oPaypalBuilder->insert($data);        }        // process payment and mark item as paid.        if (DEBUG == true) {            error_log(date('[Y-m-d H:i e] ') . "Verified IPN: $req " . PHP_EOL, 3, LOG_FILE);        }    } else if (strcmp($res, "INVALID") == 0) {        // log for manual investigation        // Add business logic here which deals with invalid IPN messages        if (DEBUG == true) {            error_log(date('[Y-m-d H:i e] ') . "Invalid IPN: $req" . PHP_EOL, 3, LOG_FILE);        }    }}

I can't get data in the database, I am sending data

<form action="https://www.sandbox.paypal.com/cgi-bin/webscr"        method="post" class="d-none" id="paypal" target="_top"><input type='hidden' name='business'            value=''> <input type='hidden'            name='item_name' value=''> <input type='hidden'            name='item_number' value=''> <input type='hidden'            name='amount' value=''> <input type='hidden'            name='no_shipping' value=''> <input type='hidden'            name='currency_code' value=''> <input type='hidden'            name='notify_url'            value=''><input type='hidden' name='cancel_return'            value=''><input type='hidden' name='return'            value=''><input type="hidden" name="cmd" value="_xclick"></form>