keydown
fires when any key is pressed and an option of Combobox is in focus
keydown: (event: KeyboardEvent, id: string | number | undefined) => void;
Parameters:
event: KeyboardEvent- a native KeyboardEvent objectid: string | number | undefined- the id of the option of Combobox in focus
Example
combobox.events.on("keydown", function(event, id) {
    console.log(event, id);
});
Related sample: Combobox. Events
Change log:
added in v7.2