Redirecting in BaseController?

So in previous Codeigniter versions I usually had a base controller that all other controllers extended from.  In that controller I would check if the user was logged in and if not, redirect them to a login page.  I'm not able to do redirecting in the base controller in CI4.  

How should I handle checking if the user is logged in and if not sending them to the login page without having to write an if statement on all of my page controllers?