Tap on the Hint icon, wait a few seconds, and a dot on the board shows you where KataGo thinks you should play. This minimalist version of Hint is now a thing of the past.
The newest version of SmartGo One makes Hint much more useful:
(1) It can show you multiple top moves that KataGo is considering. It uses the familiar color scheme from Lizzie: teal for the top move, green for other good moves, brown for moves that were considered but are not as good.

(2) It can show you the principal expected move sequence.

(3) If you like more information density, you can see top move choices and move sequence at the same time.

(4) You can easily switch between these display modes with a long press on the Hint icon.

(5) You can give KataGo more time: Settings > Computer Play > Time for Hint. If you set it to ‘Unlimited’, tap on the Hint icon again to stop computing.

(6) If you only see part of the board and the best move is off-screen, SmartGo pans the board to bring the best hint move into view.

(7) There’s now a keyboard shortcut for Hint: Cmd-K (think KataGo).
(8) Hint is now available on the toolbar in Replay mode, not just Play.
Enjoy!