How do I authenticate my tablet after an update

[AC Question]

After updating viber I have been asked to authenticate my tablet. How do I do this on my galaxy 4 android.

 

[Rukbat]

Asked by whom? (If by Viber, ask them what they mean and how to do it.)

 

[kvchau]

The same thing happened to me when I got a new phone. How did you finally authenticate your tablet.