Issue "OptInRequired: You are not subscribed to this service...." at Custom Test

[Maxim Pobihun]

Hi,
I'm new in RedLine13. 

I'm getting the following error when trying to run a custom python test:

"Automatically cancelled due to test startup error.
Not enough servers started.
OptInRequired: You are not subscribed to this service. Please go to http://aws.amazon.com to subscribe.  "

The code example custom_load_test.py I took from this RedLine13 page:
https://www.redline13.com/blog/custom-load-test-python/   

Into which service I still need to subscribe to?

I already  set up  AWS keys with  RedLine13 account.

Policy is validated as well.

Thanks in advance,

Maxim