TWebFirebaseClientDataset issue

I got this to work by:

UN-checking: AutoGenerateKey and SigninRequired

Then one of the two combinations of details I provided actually WORKED!

Why is it that we too often have to resort to trial-and-error to make stuff work ?

Firebase has a lot of configuration options & flexibility and with that also comes some complexity unfortunately.

All I'm getting now when I try to connect is a 403 error, although the tokens are being generated.

Error code : 403
Error message : Permission denied on resource project MyApp.

It's not coming from the Rules.

Any ideas?

Without any further details, it is impossible to provide useful feedback.
I would think that you haven't given access to the project to the account with which you sign-in with Google.

unfortunately, that's all the detail I'm getting from the component.