EXPORT TO NEPAL

Export made from India means, generally Shipping bill will be available, it must to be filled SB details while filing GSTR1 returns, after that it transmit data to respective ports.

YOU CAN TRY ANY ONE STEP OUT OF 3

1.   you can demand the bill of entry on mail by the nepal party 
and  you can find the all requred dtails for the gst return
like shipping bill no (SBN), & DATED  PORT CODE OF BOTH CONTRES  

2. YOU CAND DEMAD SHIPPING BILL FROM YOUR TRANSPORTER OR CHA

3. YOU CAN TRACK IT ONLINE WITH THE HELP OF YOUR IMPORT EXPORT CODE (IEC)
https://www.icegate.gov.in/DocEnquiry/iecEnq/displaySBAndBEInputPage

IN THIS LINK YOU CAN FIND THE SHIPPING BILL

AND AFTER THIS YOU CAN GO BELOW LINK 
https://enquiry.icegate.gov.in/enquiryatices/sbTrack
or
https://dgftcom.nic.in/licasp/sbdetformnew.asp

AND WITH THE HELP OF THIS LINK YOU CAN FIND THE PORT CODE ETC.

WHEN WE EXPORT TO NEPAL THROUGH LAND CUSTOM, THE BILL OF EXPORT IS FILED AT THE INDIA BORDER BEFORE ENTERING INTO NEPAL AND ONLY AFTER FILING & ASSESSMENT OF BILL OF EXPORT, MATERIAL WILL BE ALLOWED LEAVE INDIA.

THUS GET THE BILL OF EXPORT FILE SAME UNDER SHIPPING BILL

Yes u must request for your bill of export (BOE) from your CHA.