You can only use an authenticator app, if you are not using the Moss mobile app. If you use the Moss mobile app the authentication is done through the Moss app.
Why should I switch from SMS to Authenticator mobile app?
Using 2FA with an Authenticator mobile app is more secure compared to SMS messages which are vulnerable to hijacking. Also, when using the Authenticator app you will spend a few seconds less to log in and you do not depend on the mobile networks which occasionally delay or fail to deliver SMS messages to you. Once you start using the Authenticator app, you won't want to switch back.
How to set it up?
You can obviously use whichever authenticator app you like, however, we will showcase setting up 2FA with the Google Authenticator app here.
1. Install the Google Authenticator app to your phone from Google Play Store (Android) or App Store (iPhone).
2. Login to the Moss website
3. Open up your profile by hovering over your name in the left bottom corner > click on "Profile"
4. Click on the "+ Add authenticator app" and a QR-code will be shown to you.
5. Open the Authenticator app on your phone. Click on + icon on bottom right corner and choose “Scan a QR Code”. Point your phone camera to the QR code displayed on your computer screen and the mobile app will automatically create an entry named “Moss” and display a large 6-digit number. This number will keep changing every 30 seconds for security reasons.
5. Click "Continue" on your computer and enter the 6-digit code from the mobile app to the next screen. Click Confirm and you are all set.
7. Click "Close" on the confirmation dialogue.
6. Logout > login again and use your Authenticator mobile app to get the 6-digit code for the Two-Factor Authentication step.
Just in case, you always have the alternative option to login using SMS by clicking "Choose a different 2FA method" in your profile.