mode property

Set the keyboard navigation mode for the chart. Can be "normal" or "serialize". In normal mode, left/right arrow keys move between points in a series, while up/down arrow keys move between series. Up/down navigation acts intelligently to figure out which series makes sense to move to from any given point.

In "serialize" mode, points are instead navigated as a single list. Left/right behaves as in "normal" mode. Up/down arrow keys will behave like left/right. This can be useful for unifying navigation behavior with/without screen readers enabled.

API Docs: https://api.highcharts.com/highcharts/accessibility.keyboardNavigation.seriesNavigation.mode