我正在尝试编写一个简单的插件，从API端点获取一些数据。我计划从一个短代码中读取api密钥，但还没到那个程度。

我编写了以下代码。我的问题是，我如何触发代码，以便调试它以查看发生了什么？

如果这是一个简单的问题，那么接下来的问题是如何从短代码中读取api密钥？

class DATA_PARSING
{

private static $instance;

/**
 * Initializes the plugin and read some data
 *
 * @access private
 */
private function __construct()
{
    add_action(\'data\', [$this, \'fetchData\']);
}

/**
 * Creates an instance of this class
 *
 * @access public
 * @return DATA_PARSING    An instance of this class
 */
public function get_instance()
{
    if (null == self::$instance) {
        self::$instance = new self;
    }

    return self::$instance;
}

private function fetchData($apiKey)
{
    $url = \'https://api.website.com/data\';
    $args = [
        \'id\' => 1234,
        \'fields\' => \'*\'
    ];
    $method = \'GET\';
    $headers = array(
        \'Authorization\' => \'Bearer \' . $apiKey,
        \'Accept\' => \'application/vnd.website.v1+json\',
        \'content-type\' => \'application/json\',
    );
    $request = array(
        \'headers\' => $headers,
        \'method\' => $method,
    );

    if ($method == \'GET\' && !empty($args) && is_array($args)) {
        $url = add_query_arg($args, $url);
    } else {
        $request[\'body\'] = json_encode($args);
    }

    $response = wp_remote_request($url, $request);

    try {
        $json = json_decode($response[\'body\']);
    } catch (Exception $e) {
        $json = null;
    }

    return $json;

}
}