Gst missing Invoice

Ajay S.Yadav (Student) (148 Points)

16 October 2018  
Dear seniors, I have a query regarding GST. Client has not entered the gst export invoice in the return GSTR 3B and GSTR 1 for month of March 2018. Now how to tackle this situation and where to show this missing invoice in GSTR 1 & 3B and how to show Gst liability and pay the same. Plz revert. Thanks in advance