curl_setopt($lisansimo_ch , CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);
veya
curl_setopt($lisansimo_ch , CURLOPT_HTTPHEADER, array(
'user-agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.111 Safari/537.36'
));