Error: 400 while using AzureCognitive search as retriever

I have combined AzureOpenAI with Azure Cognitive search as retriever, here’s the code:

from langchain.retrievers import AzureCognitiveSearchRetriever os.environ[“AZURE_COGNITIVE_SEARCH_SERVICE_NAME”] = “xxxxxxxxxxxxxxxxxxx” os.environ[“AZURE_COGNITIVE_SEARCH_INDEX_NAME”] =“xxxxxxxxxxx” os.environ[“AZURE_COGNITIVE_SEARCH_API_KEY”] = “xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx” retriever = AzureCognitiveSearchRetriever(content_key=“content”) retriever.get_relevant_documents(“what did george lucas say about star wars?”)

but i get : ‘Error in search request: <Response [400]’

I tried changing the parameters but , i could not find the solution