MoveOutEvent: {
    direction:
        | "forward"
        | "backward"
        | "upward"
        | "downward";
}

The move-out event signals that the user pressed an arrow key or tab key but there was no navigation possible inside the mathfield.

This event provides an opportunity to handle this situation, for example by focusing an element adjacent to the mathfield.

If the event is canceled (i.e. evt.preventDefault() is called inside your event handler), the default behavior is to play a "plonk" sound.