Export of good as sample

NIKUNJ VADHAR (30 Points)

23 July 2019  
I have exported a good to one of my clients as sample but the DHL people asked for GST Invoice , I made the same adding IGST but now i am making entry in GSTR1 aking for port code . So I tracked the consignment its showing goods dispatched in passenger aircraft . So how i can make the entry in GSTR1