That is also a form of basic auth, you still pass the credentials like "username:password", optionally base64 encoded but I don't believe that's required.
Edit: actually, after looking into it a bit more, it seems like passing credentials in the url will actually cause the browser to send it as an authorization header instead. So in essence it's doing the same thing.
Not exactly 1:1. The main thing that I still miss is multi lingual typing. It's not too big a deal to just switch the languages when I need to, especially since I only use 2. But that's still more than I needed to do with Gboard or Heliboard.