S Hetjens

This plug-in restricts access to blog and feed. All anonymous visitors will be forwarded to the login page of WordPress 
before accessing the blog content. If access is restricted, rss and atom feeds will be disabled, too.
The feed can be activated as a private feed for each user. Every user will have a unique feed url to access it. That 
url is based on the username and an md5 hash of the hashed password stored in database. This plug-in will modify all 
by wordpress inserted feed urls to the user specific ones. But be carefull. If you content is confidential you should 
not activate the feed. There is no way to check which services are reading (and maybe publishing) the feed’s content.

Hetjens Registered Only

This plug-in restricts the access to blog and feed. Visitors need to login before accessing the blog. It offers a private feed for every user.

Romulo Vieira

Restrict on which categories a user can post.
It also blocks the users from creating/editing/deleting categories.
Only Admins can set other user’s categories.
Works with Block Editor and Classic Editor.
It’s compatible with IE11.

Restrict Author Categories

Restrict on which categories a user can post. Just that!

Hetjens Registered Only vs Restrict Author Categories