Gstr-1 summery for fmcg goods

One of the running kirana store. they annual turnover is more then 2cr (all sales are cash sale). they are not maintaining stock details quantity wise properly due to cash sales (all customers are end users & not possible to issue bill every time). in gstr 1 we have to give hsn summry quantity wise. they don't have quantity wise details Please suggest me for filling of gstr 1. thanks in advance