How do show different homepage for logged in users - like SmugMug's Webflow site?

Hi! I know SmugMug was built in Webflow and we’re trying to do something similar like they do where they redirect the user to a different page if they’re logged in. I was wondering if anyone had any insight on how to do this? We currently have a cookie that says whether the user is logged in or not.

Here is my site Read-Only: LINK
(how to share your site Read-Only link)

Something like this should work;

if (document.cookie.indexOf('logged_in=true') > -1) {
  window.location.href = '';