Microsoft Edge Dev and Canary builds are updated frequently with new features that are hidden or not well known. The built-in password generator tool lets you complete the task without the use of a password manager. It worked well on Google, Facebook, Target, Spotify, Spotify and Instagram, but failed to show the generator on BleepingComputer, Amazon, Twitter, or even Microsoft.com. If you want to use it, you’ll first need to enable password synchronization by logging into your Microsoft account.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-edge-is-getting-a-built-in-password-generator/