Gst Annual return Questions

1.a gst registered regular scheme dealer turnover below 2 crores limit dealer gstr9 Annual return filed compulsory or optional in f.y.19-20.
2.composite scheme dealer Annual return gstr4 filed in f.y.19-20.but dealer inward supplies details(purchases invoices)not uploaded any problems future
gst 9a in f.y.19-20 compulsory for composite dealer.