RH270 Managing Containers with Red Hat Enterprise Linux Atomic Host, RHLS is worst

The Course want one to register the RHEL Atomic Server as below :
Section 2.2 : Practice: Registering RHEL Atomic

-bash-4.2# subscription-manager register
Username: rhn-username
Password: rhn-password
The system has been registered with ID: af27f5ed-4f79-46ba-bf37-2e478b83e45b

But when you use your id, it doesnt work. No available subscription pool.
Do you need to have valid subscription(buy RHEL Atomic License) to even study the course which is part of RHLS ?

Ridiculous.
And its so unfriendly to get help for any section in RHLS.