Hi!
From @abhijeet.singh.rana the CORS problem is avoided make public to anyone the service.
Edit 1: With this solution I got access to Emulator from my App, but accessing data from Emulator UI (Auth, Functions, Firestore, etc.) it is not possible with this solution, because Emulator UI resolves some access to data using “localhost” in his internal programming that is not mapped with IDX.
Edit 2: It was possible access to Auth Emulator, but It was impossible get acess to Firestore Emulator. Has anyone luck connecting with it?
So, if you use Firebase Console or Emulator UI to setup initial data, consider create some script to fill initial data.