Connection issue for intranet environment behind proxy

[pillsilly]

`
ngrx-uml diagram --baseDir=./
Starting...
Use ts-config file: ./tsconfig.json
getMember - unknown node kind PropertyAssignment
getMember - unknown node kind PropertyAssignment
getMember - unknown node kind PropertyAssignment
Items converted
Items rendered
events.js:291
throw er; // Unhandled 'error' event
^

Error: connect ETIMEDOUT 104.31.71.56:80
at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1145:16)
Emitted 'error' event on ClientRequest instance at:
at Socket.socketErrorListener (_http_client.js:428:9)
at Socket.emit (events.js:314:20)
at emitErrorNT (internal/streams/destroy.js:92:8)
at emitErrorAndCloseNT (internal/streams/destroy.js:60:3)
at processTicksAndRejections (internal/process/task_queues.js:84:21) {
errno: 'ETIMEDOUT',
code: 'ETIMEDOUT',
syscall: 'connect',
address: '104.31.71.56',
port: 80
}

`

as seen, the execution doesn't work even if my proxy were set,
the proxy was set for the level of both npm and bash, the proxy does work for other node package which requires remote connection, includes post install scripts.

only ngrx-uml doesn't work with it.