If the Chronolator toolbar was there when you opened the document but is no longer visible, you might have hidden the Ribbon by accident.

If so, click the Add-ins tab to show the Chronolator toolbar.

Making the Ribbon permanently visible

You can make the Ribbon stay visible if you want. Right-click between any of the tab labels (Home and Insert for example) and un-tick Minimise the Ribbon or Collapse the Ribbon: