Code boxes
Screen: Settings · Security, in the Confirm it's you (code) pop-up.
What it is
The six boxes in the 6-digit code pop-up. The same pop-up confirms a new authenticator, a replacement, and the owner's own code before a reset.
What to enter
Click them, then type.
What it changes
For the dealer: Nothing by itself; it puts the cursor in the code field.
For the home: Nothing. It does not reach any home.
In the app: Nothing.