Facing 400 Client Error: Bad Request for url: https://api.novu.co/v1/subscribers/bulk

Traceback (most recent call last):
  File "/workspace/blank/tt.py", line 59, in <module>
    novu = SubscriberApi(url, api_key).bulk_create(subscribers)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/workspace/.pyenv_mirror/user/current/lib/python3.12/site-packages/novu/api/subscriber.py", line 81, in bulk_create
    self.handle_request(
  File "/workspace/.pyenv_mirror/user/current/lib/python3.12/site-packages/novu/api/base.py", line 155, in handle_request
    res.raise_for_status()
  File "/home/gitpod/.pyenv/versions/3.12.0/lib/python3.12/site-packages/requests/models.py", line 1021, in raise_for_status
    raise HTTPError(http_error_msg, response=self)
requests.exceptions.HTTPError: 400 Client Error: Bad Request for url: https://api.novu.co/v1/subscribers/bulk