How to use the diagrams.onprem.iac.Terraform function in diagrams

from diagrams.onprem.compute import Server


with Diagram("Terrascan architecture", show=False):
    cli = Bash("CLI")
    server = Server("API server")
    notifier = ConsoleMobileApplication("Notifier (Webhook)")
    writer = Bash("Writer (JSON, YAML, XML)")

    with Cluster("Runtime"):
        ECS("Input Validate")
        output = ECS("Output")
        ECS("Process")

    with Cluster("IaC Providers"):
        tf = iac.Terraform("Terraform")
        ansible = iac.Ansible("Ansible")
        cft = Cloudformation("CloudFormation")


    with Cluster("Policy Engine"):
        policy = [
            VM("Azure"),
            GCE("GCP"),
            ECS("AWS")
        ]

    server >> output >> tf >> policy >> notifier
    cli >> output >> ansible >> policy >> writer
    output >> cft >> policy