I think this part of the article they are referring to a technique to compromise a WPA3-compliant router, since they wouldn't be able to use handshake material to crack the password "offline" (meaning without having to interact with other network elements), so the way to do it is to create a rogue router which will serve as an access point to the real one, that access point will offer a canonical page (those that open as soon as you connect to a hotel/mall/airport wifi networks) that will store the info entered before forwarding it to the real router.

They can capture the handshake you make with the router and try to brute force it offline