Cron does not start using an external service, how to fix it?

Question

Task Schedulers

Faced a problem.
You need to run a php file that sends certain data to another site.
script.php file.
Inside the code

$ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_ENCODING, ""); 
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        //curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1); 
        curl_setopt($ch, CURLOPT_POSTFIELDS, array(
            'urlsite' => $url,
            'text' => $text,
            'Button' => 'get'
        ));
        curl_setopt($ch, CURLOPT_USERAGENT, 'MSIE 5');
        curl_setopt($ch, CURLOPT_REFERER, $referer);
        curl_setopt($ch, CURLOPT_TIMEOUT, 2);
        curl_setopt($ch, CURLOPT_MAXREDIRS, 10); 

        $res = curl_exec($ch);
    
        if (!$res)
        {
            $error = curl_error($ch) . '(' . curl_errno($ch) . ')<br>';
            echo $error;

        }
        curl_close($ch);

I found this external cron https://cron-job.org/ . Signed up.
Created cron is created using a regular link like so https://site/script.php .
Then I created it for 5 minutes .. I waited and looked and there no data was sent.
What can be wrong.
When I run this script via browser like this https://site/script.php enter the data is sent via cron no.