crosshair property
Configure a crosshair that follows either the mouse pointer or the hovered point.
In styled mode, the crosshairs are styled in the
.highcharts-crosshair, .highcharts-crosshair-thin or
.highcharts-xaxis-category classes.
API Docs: https://api.highcharts.com/highcharts/xAxis.crosshair
Implementation
HighchartsXAxisCrosshairOptions? crosshair;