Office ui fabric Dropdown menu does not work on keyboard press

Question

I have SPFX component with React library. The Dropdown menu is working fine with mouse onclick events. however, on pressing enter or space is not working. I am thinking of using eventhandlers such as "onkeyup" or "onkeypress", but I need help on how to render the dropdown on keyboard press.

My React component

@observer 
export default class DropdownReact extends React.Component<...>

...
//render method
  public render(): React.ReactElement<> {
    return (
       <Dropdown             
           label="Dropdown"
            defaultSelectedKey=
            onRenderTitle=
            onRenderItem= {this.CheckBoxRender.bind(this)}
             calloutProps=
             className=
             options=
             onKeyUp = ????
        />
   );
...

  }
//checkbox rendering method
private CheckBoxRender() {
  return (
    <div>
        <Checkbox 
           label=
            checked=
            onChange= />
     </div>
  );
}