How does GetButtonDown-equivalent looks like for Input System ?

Hi everyone this is the first time I use the InputSystem.

I am trying to use a button to switch the camera from FPS to TPS but when I press the action is performed continuously for each frame. I would like the key pressed to work only once as Input.GetButtonDown. I need it to be pressed, one time only.
N.B. I think the correct perform is onRelease. So in the screen the Trigger Behaviou is set to Release Only https://forum.unity.com/threads/input-system-release-only.1293426/ for more details

Here is my code and a screen:

public bool SwitchCamera { get; private set; }
InputActionMap _currentMap;
InputAction _switchCameraAction;

void Awake ()
{
    _switchCameraAction = _currentMap.FindAction("SwitchCamera");
    _switchCameraAction.performed += onSwitchCamera;
    _switchCameraAction.canceled += onSwitchCamera;
}

private void onSwitchCamera(InputAction.CallbackContext context)
{
    SwitchCamera = context.ReadValueAsButton();
}

I don’t really know why is it performed continously since, with the same configuration, I get only one performed input. However, and I know this isn’t optimal, you can use the old Input.GetButtonDown together with the new system. To enable this, go to Edit → Project Settings → Player → Other settings → Configuration → Active Input Handling. From the drop-down, select new or old or both.