Automatically refresh token using google drive api with php script

I followed again THIS TUTORIAL to upload a file on Google Drive with php, directly from my REMOTE SERVER: so I have created new API Project from Google API Console, enabled Drive API service, requested OAuth Client ID and Client Secret, wrote them in a script, then upload it together with Google APIs Client Library for PHP folder to this http://www.MYSERVER.com/script1.php, to retrieve Auth code:

<?php

require_once 'google-api-php-client/src/Google_Client.php';
require_once 'google-api-php-client/src/contrib/Google_DriveService.php';

$drive = new Google_Client();

$drive->setClientId('XXX'); // HERE I WRITE MY Client ID

$drive->setClientSecret('XXX'); // HERE I WRITE MY Client Secret

$drive->setRedirectUri('urn:ietf:wg:oauth:2.0:oob');

$drive->setScopes(array('https://www.googleapis.com/auth/drive'));

$gdrive = new Google_DriveService($drive);

$url = $drive->createAuthUrl();
$authorizationCode = trim(fgets(STDIN));

$token = $drive->authenticate($authorizationCode);

?>

When I visit http://www.MYSERVER.com/script1.php I allow authorization and get the Auth code that I can write in a second script. Then I upload it to http://www.MYSERVER.com/script2.php, who looks like:

<?php

require_once 'google-api-php-client/src/Google_Client.php';
require_once 'google-api-php-client/src/contrib/Google_DriveService.php';

$drive = new Google_Client();

$drive->setClientId('X');  // HERE I WRITE MY Client ID
$drive->setClientSecret('X');  // HERE I WRITE MY Client Secret
$drive->setRedirectUri('urn:i