Some users might be confused that the init command can only be used on Firebase RTDB from us-central1. However is possible to use any database from any region since the database_id is globally unique.

We could improve the --database_id parameter help text mentioning any database_id that could be used from any region, if the user uses the DATABASE_ID from the DATABASE_URL patterns:

• DATABASE_ID.firebaseio.com
• DATABASE_ID.europe-west1.firebasedatabase.app
• DATABASE_ID.asia-southeast1.firebasedatabase.app

We could also change the undocumented --location help text from init command to reflect that is used only to create a database if doesn't exist.