Sub Tenant

We are trying to build out our Azure account with an Azure Active Directory B2C sub-tenant. For most of the resources in parent tenant, aztfy works fine, but we're unable to get it to run against the sub-tenant. I was finally able to use "az login" to log into the sub-tenant. In the pic, the sub-tenant's parent is QA.

Because the only resource in the sub-tenant is AAD B2C directory and Active Directory, there's no Resource Group defined. So when I try to run "aztfy rg *" I get the following error in the second pic.