Setup redis clustering?

I am using redis object cache plugin and created a redis database on my webhost and connected to it. So far so good, only my problem is the redis database on my webhost has a max size so I created another redis database.

To connect to my redis cache database I entered this in my wpconfig file:
define(‘WP_REDIS_HOST’, ‘IP’);
define(‘WP_REDIS_PASSWORD’, ‘PASSWORD’);
define(‘WP_REDIS_PORT’, ‘PORT’);

On the Redis Object Cache page it says for clustering you need to use this:
define( ‘WP_REDIS_CLUSTER’, [
‘tcp://127.0.0.1:6379?database=15&alias=node-01’,
‘tcp://127.0.0.2:6379?database=15&alias=node-02’,
] );<h3>WP-CLI Commands</h3>

In which file to I need to apply these lines? Or how can I setup multiple redis databases to use?