Automatically reload schema from table

Hi,

I created a python recipe that define a SQL query and run it on a BigQuery table through the Python Bigquery API. My recipe looks like this:

DataikuException: java.lang.ClassCastException: Cannot cast com.dataiku.dip.datasets.sql.ManagedSQLTableDatasetTestHandler to com.dataiku.dip.datasets.sql.ExternalSQLDatasetTestHandler

The query runs successfully, however the shema of the created dataset is empty:

When reloading manually shema, everything works fine. But I need to automate this reload and add it inside the recipe.

I have tried this solution: https://community.dataiku.com/t5/Using-Dataiku/reload-dataset-schema-programmatically/m-p/21410

But I get this error:

import dataiku
from bq_manager import run_bq_query

query = """
CREATE OR REPLACE TABLE `project.dataset.output_table` as
SELECT ...
"""
run_bq_query(query)