credit note in gstr1

there are total10 number of transactions of supply outward for a single party. at the end of month i have issue a single credit note anounting to 4% of value of each sales
invoice in my busy accounting software.

when i am uploading the details in the gst offline tool its taking only the discount amount for the first invoice value. for rest of the 9 transaction it is showing duplication of entry.
what is the solution?