yes, /usr/bin/php is the correct vesion.
before i backup files this working fine. i dont now what going on.

Hi, I added the following code to the file in cron.php in the api directory:
<?php

// Add correct path to your countlog.txt file.
$path = 'hits.txt';

// Opens countlog.txt to read the number of hits.
$file = fopen( $path, 'r' );
$count = fgets( $file, 1000 );
fclose( $file );

// Update the count.
$count = abs( intval( $count ) ) + 1;

// Output the updated count.
echo "{$count} hits\n";

// Opens countlog.txt to change new hit number.
$file = fopen( $path, 'w' );
fwrite( $file, $count );
fclose( $file );
?>

I also added the hits.txt file there
The code itself works, I checked.(in the public_html directory)
But when triggered by cron, should the counter in the hits.txt file be incremented, or will it not work?
currently the counter in the hits.txt file does not change.

When i run cron, i get this errors:
Stack trace:
#0 /home/users/user-name/public_html/domains/domain-name/public_html/main.inc.php(23): require()
#1 /home/users/user-name/public_html/domains/domain-name/public_html/api/api.inc.php(23): require_once('/home/users/user-name...')
#2 /home/users/user-name/public_html/domains/domain-name/public_html/api/cron.php(17): require('/home/users/user-name...')
#3 {main}
thrown in /home/users/user-name/public_html/domains/domain-name/public_html/bootstrap.php on line 344
PHP Fatal error: Uncaught Error: Non-static method Misc::currentURL() cannot be called statically in /home/users/user-name/public_html/domains/domain-name/public_html/bootstrap.php:344

My cron.php file
<?php
/*********************************************************************
cron.php

File to handle LOCAL cron job calls.

Peter Rotich <peter@osticket.com>
Copyright (c)  2006-2013 osTicket
http://www.osticket.com

Released under the GNU General Public License WITHOUT ANY WARRANTY.
See LICENSE.TXT for details.

vim: expandtab sw=4 ts=4 sts=4:

**********************************************************************/
@chdir(dirname(FILE).'/'); //Change dir.
require('api.inc.php');

if (!osTicket::is_cli())
die(__('cron.php only supports local cron calls - use http -> api/tasks/cron'));

require_once(INCLUDE_DIR.'api.cron.php');
LocalCronApiController::call();
?>

Wersja serwera: 8.0.25-15 - Percona Server (GPL), Release '15', Revision 'a558ec2'