Cdktf: importing azure resources

Hi, i have most of my infrastructure build out using Terraform.
I would like to add a new resource (Azure ContainerApp Job), but try doing so with cdktf.
To do so, i would need to import the dependent resources:
-resource group
-azure container app environment and app environment storage
-azure container registry

I read that this is possible here: Resources - CDK for Terraform | Terraform | HashiCorp Developer

I am not sure though what ‘id’ means in context of azure. i dont see an id for a resource group on azure portal. as a simple test, i have written this code:

rg = ResourceGroup(self, 'rg_test_id', name=self.rg_name).import_from(id=self.rg_name)
TerraformOutput(self, 'rg_id', value=rg.id)

But when debugging, rg is None after the first line.

any documentation or help on how this should be done would be helpful.

thanks