Showing author box on post detail page

Where is your code for the author appearing (what files > category / post / single?)?

I would guess you have the author code within either a category or post template file, simply add the author code to the single template file (create single.php if you don’t have one) and remove from the upper level files.

** To answer your question (based on comments below)

You would want to create a new sidebar template (sidebar-single.php) and pull that sidebar into your single.php

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