AWS MWAA/Apache airflow: how to debug on_failure_callback itself

Have a dag like this:

import os
from datetime import timedelta

from xxx import on_failure_opsgenie
 
from airflow import DAG
from airflow.operators.python import PythonOperator
from airflow.utils.dates import days_ago
 
DAG_ID = os.path.basename(__file__).replace(".py", "")

DEFAULT_ARGS = {
    "owner": "airflow",
    "depends_on_past": False,
    "email": ["airflow@example.com"],
    "email_on_failure": False,
    "email_on_retry": False,
}
 
 
def kaboom(*args, **kwargs):
    print("goodbye cruel world")
    print(args)
    print(kwargs)
    assert 1 == 2
 
 
with DAG(
    dag_id=DAG_ID,
    default_args=DEFAULT_ARGS,
    description="Print contents of airflow.cfg to logs",
    dagrun_timeout=timedelta(hours=2),
    start_date=days_ago(1),
    schedule_interval=None,
    on_failure_callback=on_failure_opsgenie,
) as dag:
    get_airflow_cfg_operator = PythonOperator(task_id="gonna_explode", python_callable=kaboom)

The DAG fails as expected, purposefully. However, on_failure_opsgenie is not doing what it should; how do I get the logs or debug a failed on-failure-callback in AWS MWAA?