stackLabels property
The stack labels show the total value for each bar in a stacked column or bar chart. The label will be placed on top of positive columns and below negative columns. In case of an inverted column chart or a bar chart the label is placed to the right of positive bars and to the left of negative bars.
API Docs: https://api.highcharts.com/highcharts/yAxis.stackLabels
Implementation
HighchartsYAxisStackLabelsOptions? stackLabels;