AttributeError: 'str' object has no attribute 'signed_session' for Python Notebook request to CV API.

I have trained and deployed a custom vision model via an Azure ML Notebook, following the guide: https://video2.skills-academy.com/en-us/azure/cognitive-services/custom-vision-service/quickstarts/image-classification?tabs=visual-studio&pivots=programming-language-python

I'm now trying to send images to the service via the SDK Notebook code:

test_images_folder = '5point2/frames'
output_images_folder = '5point2/output'

# Load the Arial font from the Matplotlib font library
font_path = fm.findfont(fm.FontProperties(family='Arial'))

# Create a PIL ImageFont object using the Arial font
font_size = 16
font = ImageFont.truetype(font_path, font_size)

for filename in os.listdir(test_images_folder):
    if filename.endswith(".jpg"):
        image_path = os.path.join(test_images_folder, filename)

        with open(image_path, "rb") as image_contents:
            predictor1 = CustomVisionPredictionClient(end_point, pred_key)
            headers = {'Prediction-Key': pred_key, 'Content-Type': 'application/octet-stream'}
            results = predictor1.classify_image(project.id, pub_iter_name, image_contents.read(), headers=headers)

            # Load the image and create a drawing context.
            im = Image.open(image_path)
            draw = ImageDraw.Draw(im)

            # Draw the class labels and their probabilities on the image.
            for prediction in results.predictions:
                label = prediction.tag_name + ": {0:.2f}%".format(prediction.probability * 100)
                draw.text((10, 10 + 20 * results.predictions.index(prediction)), label, fill="white", font=font)

            # Save the output image.
            output_image_path = os.path.join(output_images_folder, filename)
            im.save(output_image_path)

            # Print the predictions.
            print("Predictions for", filename)
            for prediction in results.predictions:
                print("\t" + prediction.tag_name + ": {0:.2f}%".format(prediction.probability * 100))

        # Delay before sending the next image.
        time.sleep(1)

But I get the following error:

AttributeError                            Traceback (most recent call last)
Input In [114], in <cell line: 18>()
     23 predictor1 = CustomVisionPredictionClient(end_point, pred_key)
     24 headers = {'Prediction-Key': pred_key, 'Content-Type': 'application/octet-stream'}
---> 25 results = predictor1.classify_image(project.id, pub_iter_name, image_contents.read(), headers=headers)
     27 # Load the image and create a drawing context.
     28 im = Image.open(image_path)

File /anaconda/envs/azureml_py310_sdkv2/lib/python3.10/site-packages/azure/cognitiveservices/vision/customvision/prediction/operations/_custom_vision_prediction_client_operations.py:73, in CustomVisionPredictionClientOperationsMixin.classify_image(self, project_id, published_name, image_data, application, custom_headers, raw, **operation_config)
     71 # Construct and send request
     72 request = self._client.post(url, query_parameters, header_parameters, form_content=form_data_content)
---> 73 response = self._client.send(request, stream=False, **operation_config)
     75 if response.status_code not in [200]:
     76     raise models.CustomVisionErrorException(self._deserialize, response)

File /anaconda/envs/azureml_py310_sdkv2/lib/python3.10/site-packages/msrest/service_client.py:336, in ServiceClient.send(self, request, headers, content, **kwargs)
    334 kwargs.setdefault('stream', True)
    335 try:
--> 336     pipeline_response = self.config.pipeline.run(request, **kwargs)
    337     # There is too much thing that expects this method to return a "requests.Response"
    338     # to break it in a compatible release.
    339     # Also, to be pragmatic in the "sync" world "requests" rules anyway.
    340     # However, attach the Universal HTTP response
    341     # to get the streaming generator.
    342     response = pipeline_response.http_response.internal_response

File /anaconda/envs/azureml_py310_sdkv2/lib/python3.10/site-packages/msrest/pipeline/__init__.py:197, in Pipeline.run(self, request, **kwargs)
    195 pipeline_request = Request(request, context)  # type: Request[HTTPRequestType]
    196 first_node = self._impl_policies[0] if self._impl_policies else self._sender
--> 197 return first_node.send(pipeline_request, **kwargs)

File /anaconda/envs/azureml_py310_sdkv2/lib/python3.10/site-packages/msrest/pipeline/__init__.py:150, in _SansIOHTTPPolicyRunner.send(self, request, **kwargs)
    148 self._policy.on_request(request, **kwargs)
    149 try:
--> 150     response = self.next.send(request, **kwargs)
    151 except Exception:
    152     if not self._policy.on_exception(request, **kwargs):

File /anaconda/envs/azureml_py310_sdkv2/lib/python3.10/site-packages/msrest/pipeline/requests.py:65, in RequestsCredentialsPolicy.send(self, request, **kwargs)
     63 session = request.context.session
     64 try:
---> 65     self._creds.signed_session(session)
     66 except TypeError: # Credentials does not support session injection
     67     _LOGGER.warning("Your credentials class does not support session injection. Performance will not be at the maximum.")

AttributeError: 'str' object has no attribute 'signed_session'

I have checked all my credentials and they are all correct.
I am unable to use azure.cognitiveservices.vision.customvision.prediction import CustomVisionPredictionEndpoint as I am using Python.

I assume this is an SDK issue, please assist.

Thank you.