Not able to fetch Option Chain data for any Sensex stocks using BSE exchange

I’m unable to fetch Option Chain data for Sensex stocks using exchange="BSE" in the API call:

atm_strike, option_chain = tsl.get_option_chain(Underlying=stock, exchange="BSE", expiry=0, num_strikes=5)

However, it returns an error for all Sensex stocks. It seems that Option Chain data may not be available via the "BSE" exchange.

Codebase Version 3
-----Logged into Dhan-----
reading existing file all_instrument 2025-07-13.csv
Got the instrument file
Starting OI analysis cycle...
Exception at getting Expiry list as 'TATATECH'
No qualifying stocks found in this cycle.

@Tradehull_Imran ji, Pl. help