How to use the @egjs/axes.MoveKeyInput function in @egjs/axes

_initAxes(opt) {
		const yRange = this._updateYawRange(opt.yawRange, opt.fov, opt.aspectRatio);
		const pRange = this._updatePitchRange(opt.pitchRange, opt.fov, opt.showPolePoint);
		const useRotation = opt.gyroMode === GYRO_MODE.VR;

		this.axesPanInput = new RotationPanInput(this._element, {useRotation});
		this.axesWheelInput = new WheelInput(this._element, {scale: -4});
		this.axesTiltMotionInput = null;
		this.axesPinchInput = SUPPORT_TOUCH ? new PinchInput(this._element, {scale: -1}) : null;
		this.axesMoveKeyInput = new MoveKeyInput(this._element, {scale: [-6, 6]});

		this.axes = new Axes({
			yaw: {
				range: yRange,
				circular: YawPitchControl.isCircular(yRange),
				bounce: [0, 0]
			},
			pitch: {
				range: pRange,
				circular: YawPitchControl.isCircular(pRange),
				bounce: [0, 0]
			},
			fov: {
				range: opt.fovRange,
				circular: [false, false],
				bounce: [0, 0]