How to customize domain name of firebase database, auth and storage?

Question

I know that I can customize domain name for firebase hosting. But how can I customize the firebase database, auth and storage domain name? eg.

authDomain: example.firebaseapp.com => auth.example.com
databaseURL: example.firebaseio.com => db.example.com
storageBucket: example.appspot.com => storage.example.com

I tried to cname the domain (eg cname auth.example.com to example.firebaseapp.com) but this cause the https://auth.example.com shows the certificate error. can I resolve that?

Answer 1

Firebase doesn't offer the ability to whitelabel our services under your own domain.

You could choose to proxy all traffic through Hosting + Cloud Functions, but that would be a significant amount of additional work.

What is the need to offer your own custom domain on these services?