To make it work:
- Copy the content of 2sidebars folder found in the contrib folder, html files to template folder and css file to theme folder (if light version is being used don't forget to upload the css file there too.).
- After that delete the sidebar.html file from template folder.
- Then open options.html file and adjust it to your needs. Both can be enabled at the same time or just the one on the left or right.