Add a php extension

i activated the php error display, i get this:
Warning : putenv() has been disabled for security reasons in /home/vol2_4/epizy.com/epiz_27280245/htdocs/system/Config/DotEnv.php on line 152

Fatal error : Uncaught TypeError: Argument 1 passed to CodeIgniter\HTTP\URI::setScheme() must be of the type string, null given, called in /home/vol2_4/epizy.com/epiz_27280245/htdocs/system/HTTP/IncomingRequest.php on line 616 and defined in /home/vol2_4/epizy.com/epiz_27280245/htdocs/system/HTTP/URI.php:625 Stack trace: #0 /home/vol2_4/epizy.com/epiz_27280245/htdocs/system/HTTP/IncomingRequest.php(616): CodeIgniter\HTTP\URI->setScheme(NULL) #1 /home/vol2_4/epizy.com/epiz_27280245/htdocs/system/HTTP/IncomingRequest.php(184): CodeIgniter\HTTP\IncomingRequest->detectURI(‘REQUEST_URI’, ‘/htdocs/’) #2 /home/vol2_4/epizy.com/epiz_27280245/htdocs/system/Config/Services.php(609): CodeIgniter\HTTP\IncomingRequest->__construct(Object(Config\App), Object(CodeIgniter\HTTP\URI), ‘’, Object(CodeIgniter\HTTP\UserAgent)) #3 /home/vol2_4/epizy.com/epiz_27280245/htdocs/system/Config/BaseService.php(123): CodeIgniter\Config\Services::request(Object(Config\App), false) #4 /home/vol2_4/epizy.com/epiz_27280245/htdocs/system/Config/Services.php in /home/vol2_4/epizy.com/epiz_27280245/htdocs/system/HTTP/URI.php on line 625