Automatic blog creation for a limited set of users

I was reading in the blog post below something that I understood to mean there was a plugin that allowed network admins to specify some attribute associated with a user to control whether that user could create new sites or not.

I'm interested in this specifically because I want all faculty and graduate students at our university to be able to create sites - not undergraduates and not staff.

https://premium.wpmudev.org/blog/wordpress-multisite-guide/
"Automatic blog creation for a limited set of users – e.g. restrict by email or with a special code (need a plugin for the special code – see below)" (But I didn't see anything below that looked like it addressed this.)