about input box for puzzle game

Unity Engine
1

I am creating a puzzle game for mobile which require player input. However, the input box that I want is like this:
Lets say the answer of the puzzle is “dog”, and there are 3 input box for user to type in. How to make each of the input box navigate to the next input box when they have key in 1 alphabet without closing the keyboard on their screen?

Thanks in advanced.

2

I would not use input boxes as such and instead capture the keyboard input directly. You can do this by showing the keyboard yourself.