Laravel application is not working on server

I have configured my laravel v(5.4) application to the server when I run my application there it gave me the PDO class missing error so I installed the pdo after installing PDO it gave me cURL missing error so I installed cURL after this no errors are displaying just saying connection refused can anyone help me find out the real issue which is causing this issue it will be a great help. Thank you in advance.

via Chebli Mohamed