Gstr 4 annual return wrong filed

Gst registered composite scheme dealer

Sales of taxable total  turnover Rs: 8,50,000/- cgst 4250/- sgst 4250/-  tax paid shown in gst cmp-08 return filed  in 2019-2020 and auto populate gstr4 table 3(1) same turnover and same tax paid shown in annual return.

Dealer mistake in gstr4 annual return table (6)  tax rate wise outward supplies detailes zero ( nil)turnover mentioned and annual return filed in 2019-2020.

Question:

1.How to adjustment( modify) producure in gstr4 annual return 2019-2020.

2. Mistake modify gstr 9a return  in 2019-2020 or next year 2020-2021 adjustment in gstr4 annual return .