It would be great to be able to add a “sign-up” screen similar to the “sign-in” screen, this way you can change the language for two different welcome screens “sign up with your email” (non-users) and “sign in to your account” (users)
Currently, you could use the same screen and use “sign in or sign up with your email” but that’s not very common - or you could use “get started with your email” to keep it generic.