Looking for a security plugin

New to word press and I’m trying to help a friend install/configure on his site.

He’s looking for a plugin that will allow him to use htaccess login/passwords to grant access to certain categories. Basically only show the categories if the user has access.

example:

Based on 2 generic logins using htaccess.
Site has 2 different categories.

1 login will show both categories and the other login will only show 1 of the categories.

Is there something like this out there, or can someone give me some direction on what files I should look at modifying.

Thanks in advance.