Google Authenticator is a software-based authenticator by Google that implements two-step verification services using the Time-based One-time Password Algorithm and HMAC-based One-time Password algorithm, for authenticating users of software applications 

Installing the Google Authenticator

Prerequisites

There are a few things that must happen before you can continue with this setup.

• You must have 2-Step Verification set up for your Google account. If you have not completed this yet please click here and follow the tutorial.
• You must install the Google Authenticator app on your mobile device. This install is as simple as downloading the app from Google Play.
• You must install a barcode scanner. (if you do not have one installed, Authenticator will ask you to install one)

Now that you have completed the prerequisites lets jump right in and set up your device to be your mobile authenticator.

1. From your favorite browser, open the Google account security page
   • https://myaccount.google.com/security
2. Click on “2-Step Verification”
3. Under the Authenticator App section, click “Setup”
4. Choose your device type (Android, iPhone) and click “Next” to reveal a QR code
   • https://play.google.com/store/apps/details?id=com.google.android.gms   Google Android
   • https://apps.apple.com/app/google-authenticator/id388497605  Apple iPhone
5. Open the Authenticator app on your device
6. Tap on “BEGIN SETUP”
7. Tap “Scan a barcode” (if you have not installed a barcode scanner, you will now be asked to)
8. Scan the QR code that is open in your browser
9. Click the “Next” button
10. Type the code you see on your mobile device into the text box and click verify.
11. Click the Done option to complete your setup

A few things to note:

You are only allowed to set up one device at a time as an authenticator.

Make sure to never set this up on a publicly shared device.

It is recommend adding a password to your device if you set up this feature, remember that security is only as good as the person keeping it.