ML commons client generate embedding method does not work with Amazon OpenSearch service

[mohdaliiqbal]

ML commons client generate embedding method is failing. I believe it is path issue - path should be

path = '_plugins/_ml/models/'+model_id+'/_predict'

Following is the error message that I get.

RequestError: RequestError(400, 'no handler found for uri [/_plugins/_ml/_predict/text_embedding/] and method [POST]', 'no handler found for uri [/_plugins/_ml/_predict/text_embedding/] and method [POST]')

Following is the line that is throwing exception.

https://github.com/opensearch-project/opensearch-py-ml/blob/ec7e0235d9092cb26fe3d889d8ab7fae28dccefe/opensearch_py_ml/ml_commons/ml_commons_client.py#L514C1-L515C1

      1 input_sentences = ["wine for my food"]
----> 2 embedding_output = ml_client.generate_embedding(f"{model_id}", input_sentences)
      3 embed = json.loads(embedding_output)['inference_results'][0]['output'][0]['data']
      4 print(embed[:10])

File ~/anaconda3/envs/pytorch_p310/lib/python3.10/site-packages/opensearch_py_ml/ml_commons/ml_commons_client.py:490, in MLCommonClient.generate_embedding(self, model_id, sentences)
    486 API_URL = f"{ML_BASE_URI}/_predict/text_embedding/{model_id}"
    488 API_BODY = {"text_docs": sentences, "target_response": ["sentence_embedding"]}
--> 490 return self._client.transport.perform_request(
    491     method="POST",
    492     url=API_URL,
    493     body=API_BODY,
    494 )