Nginx works

50x Error

The server is aware that it has encountered an error below
 
500 Internal Server Error
 
A generic error message, given when no more specific message is suitable.
 
502 Bad Gateway
 
The server was acting as a gateway or proxy and received an invalid response from the upstream server.
 
503 Service Unavailable
 
The server is currently unavailable (because it is overloaded or down for maintenance). Generally, this is a temporary state.
 
504 Gateway Timeout
 
The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.