Codeigniter-4 not working on VPS Server

Hello Team,

The CI code/website is working fine for me on the localhost. But it's failing when migrated to the live server. 

The code is failing after reaching to below lines of code in the file ' system/bootstrap.php ':
$appConfig = config(\Config\App::class);
$app      = new \CodeIgniter\CodeIgniter($appConfig);
$app->initialize();


The call to bootstrap.php is made in the index.php page :
$app = require rtrim($paths->systemDirectory, '/ ') . '/bootstrap.php';

Could someone please help me to solve this issue?

Thanks & Regards