Turn on a Chord Diagram view (Piano, Guitar, or Ukulele) with the Chord Diagrams button in the Player controls; on Mac and Windows, from the Window or View menu.

 

Tap and hold a bar, or click and hold, to see the fingering. While the player is paused, swipe the diagram, or click the dots beneath it, to step through the other voicings.

 

For more, see Chord diagrams and scales on the iReal Pro website.