How does the Login Gate work if you are NOT using Firebase?

I can’t find any documentation on the Login Gate component, just a bunch of posts related to Firebase (which I’m not using).

Is the Login Gate only for Firebase users?

I’m using React Studio to rebuild the front-end of a (more or less) existing web application, which already has a user management system under the hood. I’m wondering if I configure the React Studio Login Gate properly, will it make it easier for the back-end developer I’m collaborating with to integrate it into the existing system, or is it better to just do a simple Email / Password / Submit form on a responsive screen?

I really like the program so far, even though the learning curve keeps hitting me over the head. It might be useful to have a wiki for React Studio. I looked and didn’t find one. Did I miss it?