Here you need to indicate the ROOT username and the password of the ROOT user which is my-secret-pw if you choose to keep the default values.
Have you tried to apply the yml file I sent earlier? Just this file with no changes, just for the sake of testing.
I’d also like to add that the first method of installation we are testing for the Workspace is installation via script, Compose method is not popular. When you had an installation via script, the domain name of your portal could not be resolved from the Community Server container.