Error while placing order via kiteConnect using place_order API

I fixed that @Nivas Now this is new error and I have changed the stock symbol but not luck .. RVHL: The instrument you are placing an order for has either expired or does not exist. this is my correct code now kite = KiteConnect(api_key=api_key)
kite.set_access_token(access_token)

# Read Excel orders
df = pd.read_csv("orders.txt",sep=",")
print("RAW columns:", df.columns.tolist())
print("\n")
df.columns = df.columns.str.strip()
print("STRIPPED columns:", df.columns.tolist())
# df['exchange'] = df['exchange'].str.strip().str.upper()
# df['tradingsymbol'] = df['tradingsymbol'].str.strip().str.upper()
df["price"] = pd.to_numeric(df["price"], errors="coerce")
df["trigger_price"] = pd.to_numeric(df.get("trigger_price", []), errors="coerce")

# — Verify symbol
inst = kite.instruments("NSE")
df_inst = pd.DataFrame(inst)
print("RVHL Details",df_inst[df_inst.tradingsymbol == "RVHL"][["exchange","tradingsymbol","instrument_token"]])
print("Exact symbol","\n", df_inst[df_inst['tradingsymbol'] == "RVHL"][["exchange", "tradingsymbol"]])

for _, row in df.iterrows():
try:
params = {
"variety": kite.VARIETY_REGULAR,
"exchange": row["exchange"],
"tradingsymbol": row["tradingsymbol"],
"transaction_type": row["transaction_type"],
"quantity": int(row["quantity"]),
"order_type": row["order_type"],
"product": row["product"],
"validity": row["validity"],
"price": row["price"],
"trigger_price": row["trigger_price"]
}
# Only add price if it’s not NaN
if not pd.isna(row["price"]):
params["price"] = float(row["price"])

# Likewise, for trigger_price if you have it
if "trigger_price" in row and not pd.isna(row["trigger_price"]):
params["trigger_price"] = float(row["trigger_price"])

order_id = kite.place_order(**params)
print(f"Order placed. ID: {order_id}")

except Exception as e:
print(f"Error placing order for {row['tradingsymbol']}: {e}")