Start the interactive console

$ tf console
>

Checking the help.

> help
The Terraform console allows you to experiment with Terraform interpolations.
You may access resources in the state (if you have one) just as you would
from a configuration. For example: "aws_instance.foo.id" would evaluate
to the ID of "aws_instance.foo" if it exists in your state.

Type in the interpolation to test and hit <enter> to see the result.

To exit the console, type "exit" and hit <enter>, or use Control-C or
Control-D.