SCN U/S 73(1)


28 March 2023  
we have received form GST DRC-01, SCN U/S 73(1). FOR LATE FILING OF MARCH-2020 3BbRETURN. we have filed the return on 23.10.20. but as per law one should claim itc within 20.10.20. we have already replied to LGSTO EARLIER, BUT NO USE. they have served the notice now and demanding of itc claimed in March month return along with penalty and interest.
kindly suggest how to reply to LGSTO.
Thanking you.