Export invoice under GST

R. CA (121 Points)

10 July 2018  
If we want to amend last month export invoice on which Gst is zero in GSTR 1 (last year invoice is of Rs. 1lakh now we want to make it for Rs. 110000).
what is the best option?Do we need to issue Debit note? or we can directly amend the invoice in the return?