Gstr 4 annual return filed mistake

A composite dealer annual  return gstr4 filed in year 19-20.but dealer mistake sales turnover amount not reported table 6 colum no.in gstr4 annual return in 19-20.

Question:

1.Dealer Mistake sales turnover amount adjustment producure in gstr4 annual return in 19-20

2. Mistake sales turnover adjustment gstr9a return 19-20 or gstr4 Annual return year 2020-2021  adjustment is correct method.