Visitor Data not return all data!

i’m trying to get Visitor Data in custom module but its not return all visitor Data especially visitor_id.

its only return this

array(1) { ["last_visit_at"]=> string(19) "2021-10-02 20:50:24" }

my block

class Hello extends MagentoFrameworkViewElementTemplate
{
    /**
     * Customer visitor
     *
     * @var MagentoCustomerModelVisitor
     */
    protected $_customerVisitor;

    /**
     * Construct
     *
     * @param MagentoFrameworkViewElementTemplateContext $context
     * @param MagentoCustomerModelVisitor $customerVisitor
     * @param array $data
     */
    public function __construct(
        MagentoBackendBlockTemplateContext $context,
        MagentoCustomerModelVisitor $customerVisitor,
        array $data = []
    )
    {
        $this->_customerVisitor = $customerVisitor;
        parent::__construct($context, $data);
    }

    
    public function getVisitorID(){
        return $this->_customerVisitor->getData();
    }
}

kindly advise.
Thanks