https://www.bleepingcomputer.com/news/google/new-chrome-for-ios-feature-locks-incognito-tabs-with-face-id/

Google Chrome for iOS is getting a new privacy feature that lets you lock your opened Incognito tabs behind your iPhone's Face ID or Touch ID biometric authentication features.

Users commonly browse in Incognito mode when visiting sensitive sites that they do not wish to appear in their browser history. However, if a user leaves their phone unlocked, someone can launch Chrome and view the currently open Incognito mode tabs.