Unable to connect to Posgresql

I'm trying to connect to Pg but for some reason it throws an exception:

//........
app.post("/some_url", (req, res) => {
  const client = new pg.Client({user: "user1", password: "password$", database: "some_db", host: "127.0.0.1"});
  client.connect((err) => {
    if (err) {
      throw err;
    }
  //.......

Here's an error:

events.js:163
      throw er; // Unhandled 'error' event
      ^

Error: Connection terminated
    at Connection.<anonymous> (/home/user1/app_123/node_modules/pg/lib/client.js:199:29)
    at Object.onceWrapper (events.js:293:19)
    at emitNone (events.js:91:20)
    at Connection.emit (events.js:188:7)
    at Socket.<anonymous> (/home/user1/app_123/node_modules/pg/lib/connection.js:141:10)
    at emitNone (events.js:91:20)
    at Socket.emit (events.js:188:7)
    at endReadableNT (_stream_readable.js:974:12)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)
    at process._tickCallback (internal/process/next_tick.js:104:9)

How to fix it?

via Dorion