In the Player controls:
iOS, Android: tap on the Mixer button (second one from the right at the bottom of the screen) to change the Count-in settings. (In case you can't see the count-in when you open the mixer, scroll down to reveal it.)
Mac: the Player controls is the right panel. (View menu>Maximise/Minimise Player controls).
Windows: in the Player controls in the right panel (View > Toggle Player controls if it is minimized at the bottom).
You might need to scroll up to see the count in area in the window.
Select Zero for No count-in; Set the volume of the count in with the slider.
The Auto setting will automatically play one or two measures - depending on the tempo allowing more time for faster tempos before it starts playing.
You can also change the instrument sound of each click.
