Those are the Openstack environment variables, also described at the STACKIT Infrastructure API docs. Using them allows users to easily try / switch to this command.
Where can you get the credentials?
Open the project in the STACKIT Portal
Open the project in the STACKIT portal in which the server is created.
Go to "Infrastructure API"
Choose "Infrastructure API" from the Project detailed menu on the left.
Create new UAT
Note down your OpenStack project ID and click on "Create new UAT".