Invoice not considered in GSTR 1

Hello ,
Sir/madam,

I had filed GSTR 1 return for quarter Jan 2018 to March 2018, but after filing I come to know that I had not considered couple of invoices while filling GSTR 1 & 3B. So I had not paid GST on it yet and even I had not shown it in Invoice section in GSTR 1.
As the financial year has ended , so how to rectify it and show it in GSTR 1 ?
I am ready to pay tax on missed invoices along with interest, but how to show that particular invoice , so that it can be reflected on GST site.

Thanking you in advance.