tickWidth property
The pixel width of the major tick marks. Defaults to 0 on category axes, otherwise 1.
In styled mode, the stroke width is given in the .highcharts-tick
class, but in order for the element to be generated on category axes,
the option must be explicitly set to 1.
API Docs: https://api.highcharts.com/highcharts/zAxis.tickWidth
Implementation
double? tickWidth;