Hi there,
I understand you would like to set a custom sidebar per category, please refer to this blog.
Since this alternative solution is using custom code, it is highly recommended to use a plugin like Code Snippets to add custom PHP code into your site without directly accessing the functions.php file. Here is an article that explains how to use the Code Snippets plugin.
Let us know if there are any questions.
We’ve not heard back from you in a while, so I’m marking this thread as resolved. If you have further questions, please feel free to open a new topic.