If you would like to add a sidebar to your Squarespace blog - this plugin by SqspThemes is for you. You will need to create a page specifically for your sidebar content - and the plugin will display it as a sidebar on your blog page(s).
Note: This is a 3rd party product and Relativist Space does not take any responsibility for this product or anything related to it.
We do offer professional Website Support on an hourly basis. Our experienced team of specialists will provide all assistance with installation and customisation of all 3rd party plugins.