Run delete query from python in BigQuery

I'm using the following python code to delete some rows in a bigquery table:

from google.cloud import bigquery

bigquery_client = bigquery.Client(project='my-project')

query_delete = f"""
    delete from `my_table` where created_at >= '2021-01-01'
"""
print(query_delete)
# query_delete
job = bigquery_client.query(query)
job.result()
print("Deleted!")

However, the rows don't seem to be deleted when doing this from python. What am I missing?

from Run delete query from python in BigQuery