CI4 in shared hosting

Hi , i upload an application in ci4 to a shared hosting in a subfolder  , when i try to access it i have this problem :


ErrorException

realpath(): open_basedir restriction in effect. File(/var/www/html) is not within the allowed path(s):

This is my url : http://eventisportivi1.altervista.org/co..._4/public/

in /codeigniter4/public/index.php add

$_SERVER["DOCUMENT_ROOT"] = "/membri/xxx/codeigniter4/public";

before: 
// Valid PHP Version?
$minPHPVersion = '7.2';

in /codeigniter4/public/index.php add

$_SERVER["DOCUMENT_ROOT"] = "/membri/xxx/codeigniter4/public";

before: 
// Valid PHP Version?
$minPHPVersion = '7.2';

thank you work fine...