crowdfunder

Sorry, one more point: The user may ultimately log into WordPress and I want them to use the firebase password. However, there may be some time between when they create their firebase user and when they log into WordPress. And in that time, I need create a WordPress user for them and save data with it that is necessary to support my application.

In other words, I cannot wait for them to log into WordPress to create their WordPress User.

Is it this?
Endpoint: POST https://example.com/firebase/v2/users/register

If so, then it seems that I have to send email/password in body. Therefore, I can only use Firebase SDK Authentication, not FirebaseUI Authentication.

Is that correct?

As I said, the user doesn’t log in to WordPress directly. My application creates a WordPress account for them and interacts with WordPress REST APIs on their behalf. The user never interacts directly with WordPress site.

You said that a new user is created when they log in. But they don’t log in, only my app accesses WordPress.

So how would I use the normal Firebase auth process and automatically create a WordPress user in the same process without the user having to log in to a WordPress site.