Problem try'ng to launch the server

[antimoroma]

I'm using node v8.12.0

If i understand correctly the documentation to execute the server with this code

const alexia = require('alexia');
const app = alexia.createApp();
app.intent('HelloIntent', 'Hello', () => {
    return 'Hello from Alexia app';
});
app.createServer().start();

we need only
npm install alexia --save

But if I try to launch the app I receive the error:
Cannot find module 'hapi'

If i install the module (apparently it's not needed from doc) i get
TypeError: server.connection is not a function

May be i'm dooing something wrong?

[JanDzvonik]

Can you try installing older version of hapi?

With command:
npm install hapi@16