Back again, still going down the local

ValueError:
******
Could not load OpenAI model. If you intended to use OpenAI, please check your OPENAI_API_KEY.
Original error:
No API key found for OpenAI.
Please set either the OPENAI_API_KEY environment variable or openai.api_key prior to initialization.
API keys can be found or created at https://platform.openai.com/account/api-keys

To disable the LLM entirely, set llm=None.
******

service_context = ServiceContext.from_defaults(llm=llm, embed_model=embed_model)

# Index setup
PERSIST_DIR = "storage-data"
if not os.path.exists(PERSIST_DIR):
    documents = SimpleDirectoryReader("data").load_data()
    index = VectorStoreIndex.from_documents(documents, service_context=service_context)
    index.storage_context.persist(persist_dir=PERSIST_DIR)
else:
    storage_context = StorageContext.from_defaults(persist_dir=PERSIST_DIR)
    index = load_index_from_storage(storage_context, service_context=service_context)

query_engine = index.as_query_engine(response_mode="compact_accumulate")

# Multi-step query engine setup
step_decompose_transform = StepDecomposeQueryTransform(llm=llm, verbose=True)
multi_step_query_engine = MultiStepQueryEngine(
    query_engine=query_engine,
    query_transform=step_decompose_transform,
    index_summary="Index summary for context"
)

@app.get("/", response_class=HTMLResponse)
async def get_form(request: Request):
    return templates.TemplateResponse("index.html", {"request": request})

@app.post("/query")
async def query(user_input: str = Form(...)):
    response = multi_step_query_engine.query(user_input)
    response_text = str(response)
    return {"response": response_text}