How do I add the Marks button to the Toolbar?

  1. Right click on a toolbar in the space where there is no button, and click on Customize Toolbars…. Select any toolbar in the Basic Toolbars list (add a new toolbar if the list is empty) and click Customize….
  2. Scroll down in the Available toolbar buttons list to find Marks. Select it and add it to the Current toolbar buttons.
    Customize Toolbar