function _disableInteraction() {
    var disableInteractionLayer = document.querySelector('.introjs-disableInteraction');
    if (disableInteractionLayer === null) {
      disableInteractionLayer = document.createElement('div');
      disableInteractionLayer.className = 'introjs-disableInteraction';
      this._targetElement.appendChild(disableInteractionLayer);
    }

    _setHelperLayerPosition.call(this, disableInteractionLayer);
  }
Add disableinteraction layer and adjust the size and position of the layer

@api private
@method _disableInteraction