SendPulse API: how to integrate in Contact Form 7?

Question

WordPress

The task of integration is set. I am not very friendly with php, I did it based on an example.
Who had experience of such integration, please tell me why this code does not work.
cf7-sendpulse.php file code

<?php
/* ----------------------------------------------------------------------------
 * Integration SendPulse to Contact form 7
 * ---------------------------------------------------------------------------- */
require("sendpulse-library/sendpulse-rest-api-php/src/ApiInterface.php");
require("sendpulse-library/sendpulse-rest-api-php/src/ApiClient.php");
require("sendpulse-library/sendpulse-rest-api-php/src/Storage/TokenStorageInterface.php");
require("sendpulse-library/sendpulse-rest-api-php/src/Storage/FileStorage.php");
require("sendpulse-library/sendpulse-rest-api-php/src/Storage/SessionStorage.php");
require("sendpulse-library/sendpulse-rest-api-php/src/Storage/MemcachedStorage.php");
require("sendpulse-library/sendpulse-rest-api-php/src/Storage/MemcacheStorage.php");
function add_email_to_sendpulse($contact_form) {

    $wpcf7 = WPCF7_ContactForm::get_current();
    $submission = WPCF7_Submission::get_instance();
    $data = $submission->get_posted_data();
    $book_id = 1717359;
    $email = $data['Email'];
    
    if ($cur_email != '') {
        define( 'API_USER_ID', '*******' );
        define( 'API_SECRET', '*******' );
    define( 'TOKEN_STORAGE', 'sendpulse-library/sendpulse-rest-api-php/src/Storage/token.txt' );
        $SPApiProxy = new SendpulseApi( API_USER_ID, API_SECRET, TOKEN_STORAGE );
        $SPApiProxy->addEmails($book_id, array($email) );
    }
}
?>

The structure of the working directory:

in the functions.php file I write:
require_once('cf7-sendpulse.php');