Symfony 4 - Use environment variable in dev and test

as part of a training on Stripe on Symfony, I am trying to set up an environment variable for testing.

So I have to set a variable to false for testing. And for other environments, the variable must be true.

So, I did this :

#.env.test:
VERIFY_STRIPE_EVENT=false

and

#.env:
VERIFY_STRIPE_EVENT=true

Next, I want to test if I have the good value.

So in my controller, I test : dd(getenv("VERIFY_STRIPE_EVENT")); with dev environment. But it returns false.

It means that I can't get the variable. Can someone help me please ?