below is a code for a plugin to intergrate to Dlercloud.com, I get an error – Failed to retrieve data from DlerCloud API. when visiting plugin setting page, what could be the issue. <?php /* Plugin Name: DlerCloud API Wrapper 1.0.1 Description: WordP

					<?php
/*
Plugin Name: DlerCloud API Wrapper 1.0.1
Description: WordPress wrapper for DlerCloud API
*/

// Include the WP_Http class
require_once ABSPATH . 'wp-includes/class-wp-http.php';

// DlerCloud API class
class DlerCloudAPI {
  // Properties
    private $access_token;
    private $base_url;
    private $http;

    // Constructor
    public function __construct($access_token = null) {
        $this->access_token = $access_token;
        $this->base_url = 'https://dler.cloud/api/v1/';
        $this->http = new WP_Http();
    }

    // Method to make API requests
    private function request($endpoint, $method = 'POST', $data = array()) {
        $url = $this->base_url . $endpoint;
        $headers = array(
            'Content-Type' => 'application/json',
            'Authorization' => 'Bearer ' . $this->access_token
        );
        $args = array(
            'headers' => $headers,
            'method' => $method,
            'timeout' => 30, // API request timeout, in seconds
            'body' => json_encode($data)
        );

        $response = $this->http->request($url, $args);

        if (is_wp_error($response)) {
            return false; // return false if there was a problem with the API request
        }

        $body = wp_remote_retrieve_body($response);
        $decoded_body = json_decode($body, true);

        if ($decoded_body && isset($decoded_body['ret']) && $decoded_body['ret'] === 200) {
            return $decoded_body['data'] ?? array(); // return the response data if successful
        }

        return false; // return false if the API request was not successful
    }

    // Method to log in to the DlerCloud API
    public function login($email, $password) {
        $data = array(
            'email' => $email,
            'passwd' => $password
        );

        $response = $this->request('login', 'POST', $data);

        if ($response && isset($response['token'])) {
            $this->access_token = $response['token'];
            return true; // return true if login was successful and access token was obtained
        }

        return false; // return false if login was unsuccessful
    }

    // Method to retrieve user information from the DlerCloud API
    public function get_user_info() {
        return $this->request('information');
    }

    // Method to retrieve managed Clash data from the DlerCloud API
    public function get_managed_clash() {
        return $this->request('managed/clash');
    }
}

// Plugin Settings Page
function dlercloud_api_settings_page() {
    $email = 'marcusvpn25feb@gmail.com'; // Replace with your DlerCloud email
    $password = 'Octoberbaobei10@2023'; // Replace with your DlerCloud password

    $api = new DlerCloudAPI();

    // Log in to obtain the access token
    $logged_in = $api->login($email, $password);

    if ($logged_in) {
        // Retrieve user information
        $user_info = $api->get_user_info();

        // Retrieve managed Clash data
        $managed_clash = $api->get_managed_clash();

        if ($user_info !== false && $managed_clash !== false) {
            // Rest of the code remains the same
            // ...
        } else {
            // If either request returned false, display an error message and the response data
            echo 'Failed to retrieve data from DlerCloud API.';
            echo '<br>';
            echo 'User Info Response: ';
            var_dump($user_info);
            echo '<br>';
            echo 'Managed Clash Response: ';
            var_dump($managed_clash);
        }
    } else {
        echo 'Failed to log in to DlerCloud API.'; // Display an error message if login was unsuccessful
    }
}

// Add the settings page to WordPress admin menu
function dlercloud_api_add_menu() {
    add_options_page('DlerCloud API Settings', 'DlerCloud API', 'manage_options', 'dlercloud-api-settings', 'dlercloud_api_settings_page');
}

// Hook the menu function to the admin menu
add_action('admin_menu', 'dlercloud_api_add_menu');