There is a box on my category page. How to remove or hide left bar?
If you want to remove this box from your category pages or hide left bar:

Visit Admin > Catalog > Categories.
Search for existing category or sub-category

Once you have found the category page, click on the Layout (tab)
Search for Left Bar. Checkmark this box, in order to hide the left bar navigation on this page.

Click Update to save.
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