Settings related to the theme are available through the WordPress customizer. Go to ( Dashboard > Appearance > Customize ) in the WordPress Dashboard for all the theme settings. Click on the specific titles to open their settings.
The method you describe I am aware of. What I am talking about is why offer an option for ‘Bottom Menu’ – https://prnt.sc/u5pahj
If there is no ‘Bottom Menu’ to display? I know how to user a menu widget in the Footer sections, but I am confused as to why have ‘Bottom Menu’ option at all?