never mind been a while since i installed nodedbb, that prompt was for database = redis not the redis db number which came later on
1/8 09:58  - info: NodeBB Setup Triggered via Command Line
Welcome to NodeBB!
This looks like a new installation, so you'll have to answer a few questions about your environment before we can proceed.
Press enter to accept the default setting (shown in brackets).
URL used to access this NodeBB (http://localhost:4567)
Please enter a NodeBB secret (09df113d-0255-48b7-8e21-c2d0eba3be54)
Which database to use (redis)
1/8 09:58  - info: Now configuring redis database:
Host IP or address of your Redis instance (127.0.0.1)
Host port of your Redis instance (6379)
Password of your Redis database
Which database to use (0..n) (0) 3
Configuration Saved OK
└── email@example.com (firstname.lastname@example.org)
Populating database with default configs, if not already set...
Enabling default theme: Persona
No categories found, populating instance with default categories
1/8 09:59  - warn: No administrators have been detected, running initial user setup