How do I send a PUP/SUB message on GCP

Question

My function below is supposed to trigger the sending of a pub/sub message. However, I get a key error. I am not sure why it is throwing this error.

def run(event, context):
    pubsub_message = base64.b64decode(event['data']).decode('utf-8')
    week = datetime.date.today().isocalendar()[1]
    year = datetime.date.today().year
    file_name = f"Times week {year}.{week}.xlsx"
    file_path = f"/tmp/{file_name}"
    data = DataIngestion().get_data(pubsub_message)
    data = pd.DataFrame.from_records(data)
    data.drop(columns='_type', inplace=True)
    for col in data.columns:
        if "Open" in col or "Close" in col:
            data[col] = pd.to_datetime(data[col], format= '%H:%M', errors="coerce").dt.time
            data[col] = data[col].replace(np.nan, 'closed', regex=True)
    check_unique(data)
    data.to_excel(file_path, index=False, encoding='utf-8')
    filetoSend(file_path, file_name, week)

Here is the error:

File "/layers/google.python.pip/pip/lib/python3.8/site-packages/flask/app.py", line 2073, in wsgi_app
        response = self.full_dispatch_request()
      File "/layers/google.python.pip/pip/lib/python3.8/site-packages/flask/app.py", line 1518, in full_dispatch_request
        rv = self.handle_user_exception(e)
      File "/layers/google.python.pip/pip/lib/python3.8/site-packages/flask/app.py", line 1516, in full_dispatch_request
        rv = self.dispatch_request()
      File "/layers/google.python.pip/pip/lib/python3.8/site-packages/flask/app.py", line 1502, in dispatch_request
        return self.ensure_sync(self.view_functions[rule.endpoint])(**req.view_args)
      File "/layers/google.python.pip/pip/lib/python3.8/site-packages/functions_framework/__init__.py", line 171, in view_func
        function(data, context)
      File "/workspace/main.py", line 92, in run
        pubsub_message = base64.b64decode(event['data']).decode('utf-8')
    KeyError: 'data'