Gst circular no 12/2017-customs

I NEED CLARIFICATION REGARDING CIRCULAR NO 12/2017-CUSTOMS F.NO 450/119/2017-CUS.IV(PT. 1)

INVOICE NUMBER AND IGST PAID AMOUNT MISMATCH.

FOR EXPORTERS :

IN SHIPPING BILL CUSTOM INVOICE IS SHOWN . IN GSTR1 CUSTOM INVOICE NO OR TAX INVOICE NO IS TO BE ENTERED

IN SHIPPING BILL FOB VALUE AND C&F VALUE AMT IS SHOWN .

IN GSTR1 WE HAVE TO SHOW FOB VALUE OR C&F TAX INVOICE VALUE IS TO BE ENTERED..