unable to post via webhook

[starblazr]

Traceback (most recent call last):
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask/app.py", line 2464, in __call__
    return self.wsgi_app(environ, start_response)
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask/app.py", line 2450, in wsgi_app
    response = self.handle_exception(e)
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask_restx/api.py", line 671, in error_router
    return original_handler(f)
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask/app.py", line 1867, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask/_compat.py", line 39, in reraise
    raise value
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask_restx/api.py", line 669, in error_router
    return self.handle_error(e)
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask/app.py", line 2447, in wsgi_app
    response = self.full_dispatch_request()
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask/app.py", line 1952, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask_restx/api.py", line 671, in error_router
    return original_handler(f)
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask/app.py", line 1821, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask/_compat.py", line 39, in reraise
    raise value
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask_restx/api.py", line 669, in error_router
    return self.handle_error(e)
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask/app.py", line 1950, in full_dispatch_request
    rv = self.dispatch_request()
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask/app.py", line 1936, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask_restx/api.py", line 403, in wrapper
    resp = resource(*args, **kwargs)
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask/views.py", line 89, in view
    return self.dispatch_request(*args, **kwargs)
  File "/root/OpenALPR-Webhook/venv/lib/python3.11/site-packages/flask_restx/resource.py", line 49, in dispatch_request
    resp = meth(*args, **kwargs)
  File "/root/OpenALPR-Webhook/apps/api/controller/webhook_controller.py", line 77, in post
    api_key = request.json['custom_data']['API_KEY']
TypeError: string indices must be integers, not 'str'

On webhook post, this is what gets dumped in the log.

ideas?