Duplicate invoice number in 2 different export invoices

Hi,

During the month of April, I generated 2 export invoices for 2 different parties. Due to some error, both invoices have the serial number "07". These were commercial export invoices and both have been shipped. Shipping bills were generated for the same. When I reviewed the shipping bills that is where I caught the issue. Both the shipping bills have the same invoice number. How do I rectify it and how do I proceed with my GSTR-1 filing for the April month?

Please advice.