I have a problem in $url = new UrlProvider(); with Phalcon Framework

Please help in this problem, what should I do to solve the problem note that the error that appears to me on the page .

Fatal error: Class 'UrlProvider' not found in C:\xampp\htdocs\tutorial\public\index.php on line 31 .

This is the code in the file Index.php : .

    // Setup a base URI so that all generated URIs include the "tutorial" folder
    $di->set('url', function(){
        $url = new UrlProvider();
        $url->setBaseUri('/tutorial/');
        return $url;
    });

And (( Tag )) not working .

     echo $this->tag->form("signup/register"); 

    echo $this->tag->textField("name");

     echo $this->tag->textField("email");

     echo $this->tag->submitButton("Register");