Spark Migrate on Testing environment

Hi,

I just want to start learning the CI4.
Within .env file, there was 2 template group of Database, default and tests.

CMIIW,
default group will be used if i set CI_ENVIRONMENT to production.
if i want to use tests group, than i have to set CI_ENVIRONMENT to development or testing ?

my question actually about spark migration.
If i set the environment to production / development, and run php spak migration, it was no error, and the default database filed with migration data.

But if i change the environment to testing, i got this error:

Code:

CodeIgniter CLI Tool - Version 4.0.2 - Server-Time: 2020-02-25 22:24:35pm

ERROR: 404
Controller or its method is not found: App\Controllers\Cimigrate::index

Please advise, how do i use the tests group database during migration?
Thank you.