in RAG project, i am using langchain, when i run the qa chain with query input, this error keep showing up!

here is the error:

—-> result = qa_chain({‘query’: question})
ValueError: Missing some input keys: {‘query’}

here is my code:

from langchain.chains import RetrievalQA
from langchain.prompts import PromptTemplate

# Build prompt
template = """Given the following context answer the question.
    Context:
    {context}
    ------------------
    Question: {query}
    Answer:"""

# LLM chain
QA_CHAIN_PROMPT = PromptTemplate.from_template(template)
qa_chain = RetrievalQA.from_chain_type(
    llm,
    retriever=vectordb.as_retriever(),
    return_source_documents=True,
    chain_type_kwargs={"prompt": QA_CHAIN_PROMPT}
)

question = "What methodology was used in this research paper?"

result = qa_chain({'query': question})

# Check the result of the query
result["result"]
# Check the source document from where we 
result["source_documents"][0]