def METHOD_NAME(self, custom_model_id):
    from azure.core.credentials import AzureKeyCredential
    from azure.ai.formrecognizer import FormTrainingClient
    source_endpoint = os.environ["AZURE_FORM_RECOGNIZER_SOURCE_ENDPOINT"]
    source_key = os.environ["AZURE_FORM_RECOGNIZER_SOURCE_KEY"]
    target_endpoint = os.environ["AZURE_FORM_RECOGNIZER_TARGET_ENDPOINT"]
    target_key = os.environ["AZURE_FORM_RECOGNIZER_TARGET_KEY"]
    source_model_id = os.getenv("AZURE_SOURCE_MODEL_ID", custom_model_id)
    target_region = os.environ["AZURE_FORM_RECOGNIZER_TARGET_REGION"]
    target_resource_id = os.environ["AZURE_FORM_RECOGNIZER_TARGET_RESOURCE_ID"]
    # [START get_copy_authorization]
    target_client = FormTrainingClient(endpoint=target_endpoint, credential=AzureKeyCredential(target_key))
    target = target_client.get_copy_authorization(
        resource_region=target_region,
        resource_id=target_resource_id
    )
    # model ID that target client will use to access the model once copy is complete
    print("Model ID: {}".format(target["modelId"]))
    # [END get_copy_authorization]
    # [START begin_copy_model]
    source_client = FormTrainingClient(endpoint=source_endpoint, credential=AzureKeyCredential(source_key))
    poller = source_client.begin_copy_model(
        model_id=source_model_id,
        target=target  # output from target client's call to get_copy_authorization()
    )
    copied_over_model = poller.result()
    print("Model ID: {}".format(copied_over_model.model_id))
    print("Status: {}".format(copied_over_model.status))
    # [END begin_copy_model]