Bluetooth Connect

Hi everyone, I’m having an issue when I try to connect in a Bluetooth device using Android Phone. I’ve tested an app from Google Play and it works, but when I call connect method from BluetoothSerial native library it doesn’t works. Could anyone help me please?

import { Component } from '@angular/core';

import { NavController } from 'ionic-angular';
import { BluetoothSerial } from 'ionic-native';

@Component({
  	selector: 'page-home',
  	templateUrl: 'home.html'
})
export class HomePage {

	constructor(public navCtrl: NavController) {

	}

	connect() {

		BluetoothSerial.isEnabled().then(res => {

			BluetoothSerial.connect('20:14:02:18:17:84');
			BluetoothSerial.isConnected().then(res => {
				console.log(res);
			}).catch(res => {
				console.log('Fail2!');
				console.log(res);
			});

		}).catch(res => {
			console.log('Fail!');
		});

	}

}

Problem Solved: I need to list the devices before I connect

can u share for me this code. i have the same problem and i dont understand, how to resolved this. how u list?