text property
The actual text of the axis title. Horizontal texts can contain
HTML, but rotated texts are painted using vector techniques and
must be clean text. The Y axis title is disabled by setting the
text option to undefined. The default value is overriden by
the lang.yAxisTitle language option.
The actual text of the axis title. It can contain basic HTML tags
like b, i and span with style.
API Docs: https://api.highcharts.com/highcharts/yAxis.title.text
Implementation
String? text;