The Bluetooth-compatible call function requires dual Bluetooth-compatible signal support, so you need to connect twice. Please follow the following instructions:
Scan the QR Code on the manual (MOST PREFERABLE - THE WATCH SCREEN/FACE) using a mobile phone QR CODE SCANNER (this can be downloaded through your app store - android or iOS) to download the dedicated application. After downloading, turn on the/your phones' Bluetooth to start the connection.

BINDING/CONNECTING YOUR WATCH TO THE APP

• Find and connect your i20 ULTRA smart watch in the app. 
• Confirm the binding
• Find the device in the Bluetooth settings of the/your mobile phone (check the device name in smart watch setting) 

Watch YouTube Video for Directions for Settings
Download App to connect fully to the watch

• Application: Scan QR code on Watch Screen with a QR code scanner on your phone
• Bluetooth for calls: support
• Bluetooth version: 3.0/4.0/5.0
• Heart rate sensor: support
• Screen: approx 2.3 inch display screen, 320*385 resolution
• Body Material: Zinc Alloy Body + IML Bottom Case
• Strap material: TUP + silica gel
• Battery capacity: 3.7V/195mAh(Watch battery life span depends on usage)
• Button method: touch + encoder button + power button + Sport shortcut key
• Engine: support
• Charging port: Magnetic charging

Feature:

• Touch Screen, Build in Flash, APP Control
• Operation System ANDROID, IOS
• Camera: No Camera
• Design Bar
• Movement Type:  Electronic
• Band Material: Silica Gel and Metal
• Case Material: ALLOY

Function:
Calendar, Alarm Clock, Week, MONTH, WORLD TIME, Power Reserve, Remote Control, Countdown, Sleep Tracker, Speed Measurement, Fitness Tracker, Calculators, Call Reminder, Answer Call, Push Message, Mood Tracker, Dial Call, Heart Rate Tracker, 24 hour instruction, Blood oxygen monitor

• model name: i20 ultra
• size: 44-49mm, 2.3 inch

Functions Alarm Clock, Answer Call, Call Reminder, Dial Call,

USE A LOW POWER CHARGER TO CHARGE - DO NOT USE A FAST CHARGER