Elastic Beanstalk CLI, how do I create the environment with an RDS instance?

According to the aws docs here, it appears when I do an eb init on a project file, I should be prompted to create an RDS instance. when I run this, instead I only see:

~$ eb init

Select an application to use
1) eb-demo-php-simple-app
2) aws-eb-deploy
3) sb-test1
4) [ Create new Application ]
(default is 1): 4

Enter Application Name
(default is "eb-demo-php-simple-app2"):
Application eb-demo-php-simple-app2 has been created.

It appears you are using Docker. Is this correct?
(y/n): y
Do you want to set up SSH for your instances?
(y/n): y

Select a keypair.
1) ####
2) ####
3) ####
4) ####
5) ####
6) [ Create new KeyPair ]
(default is 6): 5

~$

I'm using the PHP demo app from here that they provide to test out the scripts. Following the docs, I load up the EB instance, but it fails since it never sets up the RDS backend it requires.

I assume the documentation is out of date, and the CLI no longer has this functionality. The old EB cli has 'deprecated' written all over it, so I'm not using that.

How do I set up RDS with ELB CLI? Is it possible anymore?