Stepping Mode
If you have a turn based game where you want to execute code depending on which state you are in but you don’t want to run this code every frame in _process or _physics_process but rather every turn, you can use stepping mode. In this case, you will connect your state handling code not to the state_processing or state_physics_processing signals, but rather to the state_stepped signal.
Then you call the step function of the state chart whenever want to calculate the “next round”.
func _on_next_round_button_pressed():
    state_chart.step() # calculate the next round based on the current state
In C# you can use the Step function of the StateChart wrapper class:
private void OnNextRoundButtonPressed()
{
    stateChart.Step();
}
This will emit the state_stepped signal for all states which are currently active. You can connect your code to this signal to execute it every time the state chart is stepped.