Email validator code not working

[hmaddy]

i would like to create a hook to validate the customer email id when customer register the profile on whmcs. i created the following code. i need to validate the email and save the result to a txt file. but its not working. so can you please help    me.

Api mentioned on this code is dummy.

<?php
use WHMCS\View\Menu\Item as MenuItem;
use WHMCS\Database\Capsule;

add_hook('ClientAdd', 1, function($vars) {
    // Perform hook code here...

    $firstname = $vars->firstname;
    $sourceemail = $vars->email;
    $sourceuserid = $vars->client_id;
    
    // Prepare API URL
    $api_key = "myapi";
    $email = urlencode($sourceemail);
    $ip_address = "13.16.6.253"; // Assuming this is a static IP address
    $api_url = "https://api.zerobounce.net/v2/validate?api_key=$api_key&email=$email&ip_address=$ip_address";

    // Initialize cURL session
    $ch = curl_init();
    
    // Set cURL options
    curl_setopt($ch, CURLOPT_URL, $api_url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    
    // Execute cURL session
    $response_json = curl_exec($ch);
    
    // Close cURL session
    curl_close($ch);
    
    // Decode JSON response
    $response = json_decode($response_json);
    
    // Extract status from response
    $status = $response->status;

    // Save $status to a text file
    $filename = $sourceemail . '.txt';
    $file_content = "Status: $status\n";
    file_put_contents($filename, $file_content);

    // Optional: Display the status
    echo "Status for $sourceemail: $status";

    // Optional: Display any errors
    if ($status !== 'valid') {
        echo "Validation failed for $sourceemail";
    }

    error_reporting(E_ALL);
    ini_set('display_errors', 1);
});